I've almost maxed my second build at level 78 and starting to think about a third and final build as a vampire/rogue and have a few things to ask.

Do follower react to fourth stage vampire? Do they become hostile as well, even when they are your housecarl?

Should I pick a Dunmer to offset the weakness to fire resistence or should I roll a Nord for max. cold resistence?

Skills/perks to invest:

• Ilusion
  
• Alteration or Conjuration?
  
• Heavy Armour for Daedric Set or just roll with light armour?
  
• Sneak
  
• Archery
  
• One-handed

And obviously smithing and enchanting.

I don't care for the romanticism of vampires by Hollywood, but if I were gonna' do one:

I would definitely invest in Sneak - just seems to go with the whole feeding thing and the lurking in the shadows stuff.

I would pick a Dunmer for the Fire Resist (in the rare instances that I play non-humans it's for racial bonuses), plus their dark skin looks more ominous.

I would go Heavy Armor because the Daedric looks the most menacing and vampiric, but IDK if it would fit with the sneakiness for RP purposes.

The Enchanting stuff you mentioned because I would want the 92% (or greater if you use Fortify Enchanting potions) Fire Resist.