Playing a mage summoner.
1. At 1st I received full exp points for all kills by my minions--skeletal wall, demonic aide or resurrected monsters. I tested this over and over all with the same result. I got hell spikes to lvl 5 with a book and some equipment and stopped using my minions for awhile. My character is now a lvl 30 and guess what! Now I only get 50% of the exp points for minion kills. Since I had stopped using minions for awhile I can't say with certainty what the definitive event was that triggered the change.
2. It is a real blast to resurect an orc shaman. These guys will summon a whole army just to fight a few rats that aren't even hostile. And then the army stands around making orc noises; they are a riot!
3. I can't remember what my 3rd point was. Maybe I'll remember later.
The question is not, Can they reason? nor, Can they talk? but, Can they suffer?