Please, do not give any spoilers here.

Only perk-talk for the vampire..
So what abilities (star signs) would you say was like a "must" for a vampire? In your opinion.

I would say Illusion to Charm people, vampires charm you know..
And Alteration to Paralyze people when you kiss them? He he..

Guess that is it?

Depends on what your vampire is, and his strong suits. I'd get enchantment stuff to offset the health and stamina regen thing.