Gremlion: Recruiting units gives karma change once per turn once per unit. So, if you recruit barbarian each turn, you will get more karma penalty than recruiting 15 at once.
I've just found the karma value memory address with a debugger, and it turns out you are a little wrong on this one. :)
You actually only get the karma penalty for the very first time you recruit a particular unit. It's -2 for the first brigand for example, all later recruitments on the next turns have no effect. Hiring thieves gives another -2 for the first one etc. More interesting stuff:
- You are right that mood has no effect.
- Disbanding guards refunds you their whole karma penalty, so you can actually work with brigands / thieves guards in a karma neutral way. You do not get their negative karma back if they are defeated, though, only by disbanding. This can also be used to your advantage - hire +karma guards and let them get defeated. This way, you'll keep their karma bonus, but don't have to pay their upkeep anymore. Plus, you can hire them again..
- Attacking provinces has 2 karma effects. The first seems to be calculated from the attacked guards' karma. The second one seems to be the province inhabitant type (free settlement, brigand outlaws etc.). Attacking free settlements gives you 0 - 1 = -1 karma, attacking barbarians is karma neutral, and attacking brigand outlaws is 1 + 2 = +3 karma.
- Attacking a site with demons guards had no effect.
- Suppressing rebellions seems to have no effect.