SO I managed to finish the "final" quest that triggers the end screen storyline (for the LN vignette). But there is still alot of the gameworld that I never figured out. Has anyone had better luck with some of these issues?

My Party: I went with a small group and ended with a Wizard1/Bard6 and a Wizard1/Rogue6 as my PCs. For NPCs I hired Brother Fist, Two Swords and Korrac for most of the adventure (leveled them as pure Monk, Fighter and Cleric), and even tried a short stint using Mia (Ranger) for a while. I played as Lawful Neutral party, but my characters were both True Neutral. So I tried mostly to follow the "neutralish" dialogue options, but steered away from good or evil deeds, unless it seemed in my best long-term interest to do otherwise.

Unsolved Quests
Walking in their Footsteps - the Lizardmen of the Southern Swamp told me they didn't kill the caravan members, but that is all I learned. But I never could turn in the quest to the Bailiff.
The Grassy Knoll - I went and notified the Baliff about what was going on, and he tasked me to solve it. But when I went back outside, Billy the Tracker was nowhere to be found. I checked all walls and towers. Naughta.
Who's Raiding the Trading - I got as far as questioning the Cavalry Captain about what happened and he told me about the Curate. All leads dried up after that and NPCs had nothing further to say. Neither Bailiff nor Guild Master would let me turn in the quest.
Take Your Pick - well I got caught stealing the armor form the wounded Dwarf, and the others (including Korrac) turned hostile, so I suppose this one was my fault.
The Great Demancipator - just heard about this one, but didn't accept, because I didn't want to antagonize the Money Cow - I mean the Keep Inhabitants. Did anyone try it?
Dazed and Amused - I never found any entertainment for Lord Axter. Other than hawking some stolen weapons there, I didn't find much to do at the Thorp at all.

Untried Quest Arcs
Kill the Yapping Dog - I didn't kill the dog, but Lady Maeri gave me the next quest anyways. What would have happened?
Slay the Defiler of Women - I chose to get him cured instead. Then I gave the vial of obviously unholy water to the Druid. Anybody else try something different?
Arachnophobia - after finding the merchant in the cave he pleads to be rescued and I answered "what's in it for me"? But I had already joined the Merchant Guild, so this resulted in an auto-refusal to help him, and we left him stranded down there. I assume there is another ending?
Lizardmen vs Predator - I chose to hunt down the Black Dragon. Anybody just attack the Chief instead?

Unresolved Questions
1. So obviously locked doors need keys. But there are a heck of a lot of doors I never found keys to. I only ever found the Kobold Chief (looted), Bugbear Chief (looted) and Corporal's Key (pick-pocketed), and as far as I could tell the Bugbear key didn't open anything in their cave.
2. Not much to do in the Inner Bailey: talked to the Cavalry Captain, stole the Wizard's Book, got a Masterwork weapon. Really? That's all there is? It's huge!
3. Never found the Banker nor the Jewler, though I suspect they were among the prisoners locked up in the Keep dungeon (the prisoners wouldn't talk to me much). Any clues?
4. Never made it past the Acolyte watching the door in the Priest's Apartment. He always turned me away.
5. Never found any way to fool the guards into letting me enter the Inner Bailey. Really? With a Disguise Kit (20 Diguise skill), the Bailiff's ring and equipped with appropriate shields/capes/armor (I even mugged the Bailiff and stole all his stuff)? I only got past them once when the Bailiff told me to get my quest reward, and then was no longer allowed in.
6. In trying to enter the Inner Bailey, I managed to get myself thrown into jail for impersonating a Guard. I paid the fine and was released, but is there any other way to get out of the cell?
7. Never met nor saw the Castellan. OK, but from the early dialogues one sort of assumes eventually you will progress up the quest tree and finally do something important for the Castellan in service of the Keep? Any clues?.
8. Never found anything interesting/useful in the graveyard/mausoleum. Come on. there must be some reason they included it.
9. Never found anything in the two deserted caves immediately in the upper right corner of the map of Caves of Chaos. They looked like maybe Giants lived there, but they wer deserted every time I checked.
10. The end screen story says that I left a Mad Wizard alive somewhere. I never even heard about him, so no clue where that would be.
11. I had a random encounter with an NPC Ranger named Aareon hiding in the forest. But he wouldn't talk to me until I dismissed Mia from the group. I know he was hirable from the dialogue, but I never saw him again after that.
12. I joined the Thieve's Guild by talking to the Mystic in the Outer Bailey, but as far as I could tell it had zero efffect on anything that happened thereafter.
13. I kept ruining the Wolf pelts when looting after combat. I never dd figure out which skill would prevent this.
14. Never did figure out the significance of all the cats hanging around.

Recruitable NPCs These are the ones I know about. I didn't learn the stats for all of them:
Brother Fist - (lvl2 halforc Monk) - S16 D12 C10 W17 Ch9 in the Church (day) or the Pub (night).
Two Swords - (lvl2 human Fighter) - S17 D11 C13 I10 W8 Ch14 in the Pub (night).
Korrac - (lvl1/1 dwarven Fighter/Cleric) - S17 D10 C21 I11 W16 Ch10 in the Pub (night).
Mia - (lvl3 liontaur Ranger) - S19 D10 C14 I10 W13 Ch11 near the Raider's Den.
Milo - (lvl2 halfling Sorcerer) - ??? in the Pub (night).
Lorin - (Druid) - ??? at the Forest Temple.
Robin Graves (lvl1 human Necromancer) - ??? in the Undertaker's house (night).
Angela - (lvl 2 halfelf Bard) - ??? at the Traveler's Inn upstairs.
Aareon - (Ranger) - ??? random encounter on World Map.

Just a heads-up:
A lot of tips and clues to the unresolved quests I mentioned above can be found here.