Two Worlds Pacifist Run - Thabarkin Citadel & Pale Stone Cave

Thabarkin Town is the castle-like citadel found south of Komorin Village and southeast of Covengor. You will probably have seen it in the distance while exploring the mountains, and it is a good place to go for many rewarding pacifist run side quests.
Thabarkin's citadel-like enclosure seen from the northern mountains in Thalmont
House Skelden (the regents from Cathalon, who many consider usurpers over the native Karga Clan of Thalmont) is in control of Thabarkin, but they won't prevent you from entering the main gates.
Approaching Thabarkin via the northern roads
Inside the Gates of Thabarkin:
After entering the Thabarkin gates and walking a short way into the citadel, you can find a man named Brogh Ardna, the quartermaster of the Skelden-controlled Thabarkin town. As you may have learned in Covengor Village, the Skelden house has banned alcohol in the region, but Ardna considers it a practical necessity to supply his men with the stuff regardless of the ban. However, he is under the impression that his supplier Dras Beclem has defaulted on his obligation to deliver the alcohol.
Quartermaster Brogh Ardna, describing Dras Beclem as a man who"does not walk, but slithers in a pool of slime, like an eel."

If you already visited Dras Beclem in Covengor, you'll know that what really happened was that a bandit stole the moonshine from Beclem's courier. However, all you have to do is confront the thief and demand he give up banditry and hand over the moonshine, which he'll do without a fight.  (See the Covengor section for details.) Whether you visit Ardna or Beclem first, bringing the moonshine recovered from the thief + the moonshine given to you as a bonus reward by Beclem will get you enough bottles to sell to Ardna to also solve his quest, and receive some gold when he buys your whole stock.

As you walk a short way onward into Thabarkin, you'll also meet one of the mysterious "Stranger" paladins, who have taken an interest in your quest. (You can speak with them for some interesting dialogues that somtimes foreshadow future events, but they won't give you any quests.)

The Thabarkin Merchant's Guild
You'll meet a merchant named Pol Getber outside the Merchant Guild, and having a conversation with him is enough to gain increased reputation with the Merchant's Guild. The Merchants are one of the best factions to gain easy pacifist run side quests from.

Getber will tell you about the Guild's history, suggesting that you also speak with Ion Furvo inside the Guild Hall for more work.
Speak with Pol Getber outside the Guild Hall for reputation with the Guild.
Speaking with Getber may be enough to get inside the Guild Hall and initiate these, but if not, you can also gain reputation with the merchants in the pacifist run quests to help Dras Beclem in Covengor (to scare off the bandit and recover the stolen moonshine), and Veran Korstill in Komorin (to deliver the Moon Eye Crystal from the ruins of Brumhill).
Once you gain some reputation with the Merchants, you can unlock a quest chain here inside their Thabarkin Guild Hall
"Earning Trust"
Inside the Merchant Guild building, Furvo will offer you a job to take sensitive Guild  documents to his associate Samon Veller at the Guild Hall in Cathalon (the largest city in the South).
However, the Merchants will warn that the criminal Giriza are eager to get their hands on the Guild's documents, and have already caused some of their other couriers to disappear. Agreeing to deliver the documents will initiate the quest called "Earning Trust."
Samon Veller gives you a quest to deliver sensitive guild documents
Delivering the documents to Veller when you reach Cathalon will reward you with gold, experience points, and increased reputation wiht the Merchants. He will also offer you another in a sequence of courier-missions for the Merchant's Guild that can also be completed without any violence. (You can find other details in separate sections on Cathalon, Quidnar and Ashos, since the quests will send you to each of those cities.)

Ged Sammra: The Missing Son
Back outside the guild in the city streets, you can find an old man named Ged Sammra. He is very concerned about his missing son Myron, a gifted prospector who has gotten mixed up with a band of mercenaries led by the norotious Hagrast Wisp. (Details about the quest are in the section on the Eastern Thalmont Mountains, and you'll need to visit the camp of Hagrast to find out what happened to Myron.) When you return to Ged Sammra with the news, you'll receive experience and increased reputation with the Karga Clan. (This is one of the pacifist run quest you could use to gain enough reputation with the Karga Clan to get into their secret fortress covered in its own section, but there is also another closer to Thabarkin at Pale Stone Cave, described below.)

The Mage Quarter:
You'll meet a number of mages who congregate here, including two who can give you good pacifist run quests that can be solved without using violence. (Note that if you find the mage quarter late at night but don't find anyone there, the mages will all eventually return there again the next morning.)
Examining an illuminated mage tome at the Thabarkin mage quarter
You will also find mages here who can train you in Water and Earth magic, in exchange for some gold. Note that these skills cost only a few hundred gold at low levels, but the price will be scaled up as you gain levels, so the sooner you learn them, the better. (After you learn any magical discipline or other skill for the first time, you will unlock the ability to invest your own skill points into that skill without requiring a trainer.) 
This Thabarkin mage can train you in Earth and Water Magick

The Water and Earth magic disciplines are probably the most valuable pacifist run magic disciplines early in the game, since they enable you to cast Earth Chains at level 1, and our favorite "Freezing Wave" spell at level two of water magic. (Later on, though, the level 16 Air Magic spell "Ressurection" will allow you to bring anyone who dies back to life, so you might also want to plan for that in the long-run.)
You will also find a special type of mage called a "Soulpatcher" here, and if you pay him some gold, he can randomly unallocate skill and attribute points so you can re-allocate them yourself in whatever way you want. (This means you can theoretically rebuild a character nearly from scratch and try radically different builds in the same run, as long as you have enough gold to keep paying for "regressions" from the Soulpatcher.)
A Soulpatcher mage
If you use a Soulpatcher, just make sure to pay attention to which skills you had before the random de-allocation of points, since the regressions can sometimes remove even level 1 of skills you start with (like horse riding, sneak, or magic), making it impossible to use those skills until you plug the points back in again (which seems to work fine).

As for the pacifist run side quests:

Rama Erandar's Stolen Mage Staff:
Rama Erandar is a kindly old earth mage who was attacked by some Groms while traveling the roads between Gorelin and Covengor. He survived the encounter, but is very upset that the Groms stole his staff from him. (He'll mention the the staff isn't worth much to anyone else, but that a mage's staff is "a part of his very being," and promise you a reward if you return it to him.) Agreeing to help him will initiate the quests "A Missing Staff" and "Mountain Tribes."
Rama Erandar, in the mage quarter of Thabarkin
Erendar is convinced the Grom fiends came from a camp in the Northwest, and you'll find it northwest of Convengor high up in the hills.
The Grom camp where you'll find Rama Erandar's stolen mage staff
The "Archmage Earth Staff" that the Groms stole from Rama Erendar is lying on the ground between their sacrificial mound and their cookfire, but you can recover the staff without a fight if you have enough stealth/sneaking skill. Alternately, you can just run in and grab it, then run away again, as long as you've got enough stamina to withstand any Grom arrows that strike you. (A potion can be used to add temporary defensive power.)
(We managed to use the sneaking skill to get into the camp and snatch the staff at night without being seen, and also stole the horned goblin totem and magnesite crystals— but got caught at the end trying to also steal the horse tethered near the camp. However, we still managed to get away without fighting, and found that the hostile Groms eventually give up the chase after you ride far enough from their camp.)
Returning the stolen mage staff to Erendar will cause him to express his gratitude and reward you with gold, experience points, and increased reputation with the Society of Mages.

Daron Moreti: The Dragon Scale
The mage Daron Moreti found a short distance from Erandar will tell you that he's working on a "complex experiment" that requires a dragon scale. He won't confide the exact nature of this experiment (since he fears the information may be passed on to "undesirables") but will offer to reward you if you bring him the Dragon Scale.
Daron Moreti offers you a quest to bring him a Dragon Scale.
The easiest place to pick up a dragon scale without any fighting is probably to visit the Brotherhood Outpost in the northeastern mountains: Dragon scales can be found on the ground there beside huge dragon skeletons, but without any need of battling living dragons. (See the separate section on the Rusty Ogre Lodge & Brotherhood Outpost for more details about the outpost, including other pacifist run quests you can get in the area.)
When you return a Dragon Scale to Daron Moreti, he'll reward you with gold, experience points, and more reputation with the Society of Mages.

The Thabarkin Dungeons
You may notice the entrance to the dungeons of  Thabarkin while exploring the city: To be efficient, you'd probably want to return here after you first visit the entrance to Pale Stone Cave south of the city, since you'll meet a man who will give you a pacifist run quest, and give you a key to unlock the inner gates found deeper in the dungeons. (See below.)

Pale Stone Cave & The Secret Passage
If you ride out of the Tharbarkin Gates and south over the upper roads following the cliffs, the road will eventually wind downhill to the entrance to Pale Stone Cave.
Following the cliffside road south of Thabarkin toward Pale Stone Cave
You'll meet a young Karga Clan operative named Eras Brakalet standing outside the entrance to the cave. Brakalet will have already heard about your activites at Throglin Temple and Komorin Village, and will give you a lot of interesting information about why he thinks the Skelden House has conspired to occupy Thalmont (unearthing Dwarven artifacts being one motive).
Eras Brakelet, who you'll find here next to the entrance to Pale Stone Cave, south of Thabarkin
After this, Brakalet will ask you to help open the underground Thabarkin passageway connecting this cave to the Thabarkin dungeons, and give you a gate key for this purpose. (Brakalet's motive for doing this is to enable Karga operatives to get inside Thabarkin to gather intelligence about the Skelden's operations, by the way— not to sneak armed forces inside for an assault that will cause any deaths.)
Brakalet will also warn that the cave is full of skeletons that forced him to retreat when he tried to do this mission himself.
Eras Brakalet talks about the Skelden House that has displaced the native Karga Clan as regents of Thalmont
To solve this quest, you can ride back up and re-enter the citadel, then find the dungeon entrance inside the city walls. After entering the dungeons, you can explore it to find two gates that you can unlock with the key given to you by Brakalet.
Inside Pale Stone Cave
You can reach the cave entrance again by sneaking through the tunnels, and can get past all the skeletons inside without being seen. (However, if your sneaking skill isn't high enough, or you prefer to be speedier, you can also just run past the skeletons, as long as you don't let them cluster together and block your path.)
Sneaking past skeletons inside Pale Stone Cave
When you return to the entrance of Pale Stone Cave and speak to Brakalet again, he will reward you with gold, experience points, and increased reputation with the Karga Clan, enabling you to get inside the Karga Fortress found in the Northwest, as well as the Karga Supply Cave. (See the separate section on the Karga Clan mountain fortress for other details about what can be done there.)

The Thabarkin Crossroads Inn & Future Access to Gorelin Village
This is one more important place to visit just outside Thabarkin Citadel, further south down the main road past the turnoff up to the Thabarkin gates.
You'll find two Giriza operatives named Stork and Keshi Lono at the Crossroads Inn. We covered the details in a separate section on the Crossroads in and Gorelin Village, as we found that Stork and Lono's quests are probably the best means of getting enough reputation with the Giriza to be let inside the Giriza-controlled Gorelin Village gates. (They will also let you gain the optimal amount of nonviolent quest rewards from related quests you can get at the Excavations.)
Gorelin Village seen from above, with Thabarkin further to the east.