Most of this is entirely up to the GM to decide.
Vampires are notorious for hiding their true nature from normal folk, so making them have pale skin and red eyes means they will always need extra magic to do what the vast majority of vampire fiction tells us they should be able to do normally. I wouldn't add red eyes or pale skin - well, maybe somewhat pale but not inhumanly (etc.) pale.
You're probably thinking more of the nosferatu, anyway. They're vampires, but a different kind - see Bestiary 4.
Coffins are purely optional. The rules reference a coffin but don't explicitly state one must be used. In the literature, most vampires only use coffins for traveling (it's convenient if normal people come snooping around in the daylight and find a "dead" guy in a coffin) or for purely personal reasons (trying to act all tough and angsty). Many vampires just sleep in beds in a room with no windows and some just dig a hole in the ground and bury themselves during the day. Wherever the vampire last slept would be the place it must return if gaseous.
Blood drinking is also varied in the literature and not specified in Pathfinder. Some stories the "good" vampires drink animal blood instead of human (though it is often described as tasting bad) and in other stories it doesn't work at all. Being able to live off of sheep makes it much easier to hide among normal people without murdered bodies and suspicious bite marks giving them away. Certainly, if a Pathfinder vampire cannot drink lesser blood, it must not be limited to humans only; I would limit it to the same creature type as the vampire's base creature type (so a vampiric drow wouldn't have to come to the surface world for human food, and a vampiric pegasus could feed on other magical beasts and wouldn't have to hunt down humans for food).
Eating normal food is also not specified in Pathfinder, but most vampire literature has this as a no-no for them. While it's not in the template, it would probably be fun to play it that way.