Vampires and the Bleeding System

[DyssalC]

My current thoughts regarding vampires:

• Humans have 500u of blood to start with. Obviously, something's gotta change in the transfer of blood to vampires, because you can't have vampires drain one dude to be at full power. I'm not entirely sure where to go here - have some bloodloss while draining someone, so you only get x units of blood for every y unit drained? Change the numbers for vampire powers entirely?
  
• I definitely want vampires to be able to drink from bloodbags. I'm thinking that since I'm going the "synthblood" route for bloodbags atm, they'll be worth way less than fresh blood, or just make the vamp gag and be really obvious or something.
  
• I like the idea of letting vampires heal bleeding/blood loss with their own blood pool, but more thoughts on this are always appreciated.
  
• With the blood system, I feel like vampires could get special powers or new effects from some of the changes in the game. More power from spilled blood around them? Special considerations in the system itself? I have a commented out clause in the bleeding code for checking if the person bleeding is a vampire, but I've yet to think of anything that could go there that I like.

As always, your thoughts and suggestions are way helpful here and really appreciated.

Ideas from a person who hasn't played vamp in about four months:

-Give vampires an extended blood pool, about 750u-1000u.
-Vampires do not suffer blood loss from cuts as badly as normal people do, and only see negative effects from lack of blood when they get to <50u.
-Vampire abilities cost blood (or in the case of things like Cloak of Darkness require a certain amount of blood for the mutation to be active).
-Vampires gain .1u-.2u per 1u drained from a human, meaning one FULL feeding gets the vampire 50u-100u of blood.
-Starlight causes the vampire's blood to evaporate in addition to doing damage, as their blood is boiling from the star light, a loss of 5u-10u per tick in space.
-Church functions similarly to a lesser extent, losing 3u-5u per tick.
-Chaplain blood draines .5u of blood per 1u consumed.
-After not feeding for a while, all blood over 500u-600u slowly drains, starting at a rate of .05u-.1u per tick and speeding up to about .5u per tick, meaning the vampire must feed.
-Holy Water causes the vampire to lose 2u-3u of blood per 1u applied.

With this sort of system the ability costs would have to be something low, but this seems reasonable to me despite the fact that it is inspired by sleep deprivation.

Or it could be terrible and I could be terrible.