I like a lot of these suggestions, but a few concerns:
*The more damaged armor becomes, the more hp damage characters take on hit. To me, that makes your suggestion for the indomnitable perk less than ideal. A single hit from an orc can all but destroy even good armor, so having to be hit again to get use out of the perk would be a death sentence. I could see making it last for more turns than it does on use.
*Exp gain should absolutely not be dropped. If the player is supposed to get used to losing soldiers, and ok with losing entire games, then it shouldn’t take forever to build a combat ready veteran. Your suggestion for the Veteran Hall could mitigate some of that frustration though.
*Early game is tough enough without deadlier 2h raiders/thugs.
*I strongly doubt that they will add new factions, but I do like the suggestion.
*I love your suggestions on quest generation. There absolutely need to be more on offer. I’m still not sure why I can’t take more than one quest at a time.
*It makes sense that the AI targets characters with the lowest def. I’m definitely looking for a high percentage when I’m picking a target. I certainly don’t consider it cheating. I do wish there was more variability than the predictable ranged turtling, but even that makes sense.
*I like the difficulty of obtaining named items, so I’m not too keen on the reliquary idea. If anything, the frequency of these items popping up in armories should be dropped and the player should be able to find multiple at once by raiding borderland camps.
Most of your quality of life improvements are great, but I’m a bit less excited about some of the leveling suggestions. I’m pretty sure that some of the level up rolls are capped for the sake of balance. In that vein though, the player should absolutely know if that 12,000 hedge knight has a club foot, and said knight should have a much better likelihood of being very talented in certain stats. He’s survived this long hasn’t he?
Some of your perk suggestions, like retrain, I love. Others, like Deathless not so much. It’s implied that the merc band is a human group fighting horrifying forces far larger than themselves. It’s a central feeling of the world since even the noble houses could crush you if you angered them. The band has no special relationship with undead or foul magic to justify the perk.