The vampires are the result of a VX Virus. Vampires here can be awake during the day, crosses don't faze them, holy water might tickle at its worst, priests taste pretty good most times... Here we come to sunlight. I want to say that no, sunlight doesn't cause them to burst into flame and be reduced to ash. And generally speaking, that's the truth. But the mind's pretty damn powerful. There are probably some older vampires out there (or maybe even pretty new vampires that have been brought up wrong) that believe whole-heartedly that if they walk into the sun they'll be rescinded to ash. And they would be, simply because that belief was so strong. There's a passage I want to quote for that from this book Of Saints and Shadows but I'll have to dig the book out first.
Vampires are stronger and faster than humans as a base score. About twice as strong as they were in life, plus whatever strength score they have added on. Speed goes along the same lines, agility's stepped up a notch but only one. If you weren't flexible in life you're not gonna be much better as a vampire.