It's only Dead Thrall (the master level conjuration spell) that is limited to people.  All the other necromancy spells work on everything as long as they aren't too high in level.

As far as mods I have no idea though I do know there is a mod that allows Dead Thrall to affect more than just people.

Hope that helps.

Ha, so it's only the master spell. Silly me. As I said, in all five years I've been playing Skyrim I never used necromancy. Thanks, Vargr. :)

(Except for tests) you're not alone.

Welcome to the DAHK SYEED Karver.

"Progress requires experimentation." ;)

Necromancy is the best-mancy, you're missing out.

I've got a glitch with Serana in Volkihar undercroft. The first time, she was stuck in combat, aiming at something on the other side of the infected bone-corridor. The second time, she was stuck casting vampiric drain after we fought death hounds and a feral vampire. Has anyone else had this issue?

I got through that glitch, but now the game freezes when I travel the coast from Northwatch Keep to Solitude. The differences between now and the last time I did that are that Serana's with me, and I'm collecting Nirnroot along the way.

Is it consistently freezing at the same point each time, or does it randomly freeze at any point along the way?

It seems like it consistently freezes a few feet past Orphan's Tear, although not the first time, when Serana wasn't with me.