Hopefully something quick:

Are all summons summoned from magic, summons summoned from items, animal companions, and familiars always set to Full Death, or is there now a way to change that?

They'll attack with whatever your setting is, i believe. If you're on FD, they're on FD. If you're on subdual, they're on subdual.

(If it doesn't work that way, give us a shout, i suppose it's not something that gets tested a lot)

I'm going to echo what NC said. They should adopt the mode of their master, but as this is something that isn't testing a lot, it's possible that my fix here was buggy. Give us a shout if it's not working this way. :)