Oh man, that's a big list. Thank you. I'll comment on some things that I think could be interesting but I'll probably like 40 items to my to-do list.
A lot of things that only show up once or twice tend to cause trouble. There are many other bugs you didn't find that I'm aware of but you hopefully didn't encounter. I just didn't have enough time for everything. At least that screenshot is kind of funny even if the problem is literally a 1 where there should be a 0 and I'm not even kidding.
The way resigning works is basically the intended way to grind if someone is really seriously stuck. It's inspired by Shining Force where you even had a skill specifically designed to leave battles halfway through and keep the experience. You could even find a secret character in the process. I'm not sure it's the best, but I'd rather have the game be too easy than too hard. You also get extra money if you lose a fight but I can't fault people for not knowing that because I don't have a tutorial.
I'm impressed you managed to reach the second form of Brunner. It's incomplete at the moment because I didn't expect anyone to really find it yet. Reviving in general is kind of buggy at the moment, I probably broke something yesterday.
Finally, on the topic of AI. Gazia hates Rebel Angels so that's not a coincidence, Ermine isn't safe either. She also likes to pick Finnegan when she uses her "defend me" ability. There's another interaction with her that I won't disclose.
Thanks for playing!