Two quest bugs first.
1. Got a quest where some woman's husband was taken by the butchermen or whatever, went to the location and was killed. Came back a few turns later with proper support and finished the battle, but got no reward and the quest starting location was already gone. Not sure if that's intentional.
2. Quest where the spider bites the cow and you ask to see the mother. I picked the "Rise and be healed (-50 mana)" option, then the next line I got was about telling her you killed the spider before she dies (I never killed any spider) and the quest was finished with the two units joining me.
Third bug is kind of strange. I was playing as Lady Irene with all base leaders on a large map. I had only found 2 other leaders so far, Gilden was not one of them. Then out of the blue Gilden (who I haven't met or seen) sends me a war declaration message and then starts throwing insults the next three turns in a row. I know I hadn't seen them because I was sort of trapped in a tiny area between two giant armies of spiders and could see every inch of my area on one screen at the time. I'm a few dozen turns past that point now and done a lot more exploring and still haven't seen them.