I think we could do with a quick list of trait bugs:

Of course, there's the double combat trait bug for starters. If you fight in manual combat, all trait triggers are checked twice.

GeneralLostHPRatio trigger is bugged so that it wors differently in auto and manual battles.

Heroic saviour and shieldbearer ancilliaries use GeneralLostHPRatio as a percentage (0-100) when it should be a ratio (0-1.0).

GeneralFoughtInCombat trigger doesn't work properly. Affects coward traits.

Good farmer traits have very high thresholds, making them impossible to gain without farming temples and extreme luck/micromanagement.
Bad farmer traits have very low thresholds, making them very easy to gain. Swapping the good/bad farmer thresholds would make it work sensibly.
Poor Assessor is perhaps a bit too easy to gain too which especially annoys newbies who don't understand exact triggers. Increasing the threshold or trigger chance would be a good idea.

And since no-one's mentioned it yet: The difficulty levels are bugged, making it easier on V.Hard for some reason (tested in 1-on-1 custom battles)!