As I said, Urban Fantasy is mostly cutting out the urban part by design as instead of engaging with all the aspects or urban life they get sidelined by having a parallel society with much fewer rules and capabilities and thus allowing for more combat without worry.
I suspect this has more to do with RPGs being based on violent conflict resolution rather than a weakness of the genre itself.
Vampires in rural areas don't have enough people to feed on in sufficient quantity to maintain a secret society.
Vampire points this out.
Food supply isn't the only limit. There's also things like the logistics of keeping a criminal conspiracy secret. The more members, the more difficult it is to keep secret. Urban fantasy often depicts magical conspiracies with far larger populations than they should rightly be able to conceal. If you give them perfect magic that lets them maintain secrecy forever by arbitrarily altering reality as desired, then you run into the issue of "why does anybody still have free will?"
Even assuming that the paranormal is kept hidden by a constant background effect, that doesn't mean the muggles are going to ignore the crimes committed. Even if most muggles refuse to believe that vampires (or w/e) exist, that doesn't mean they won't think that any real vampires are actually cult fanatics who believe themselves to be vampires.
Depending upon setting, animal blood may or may not be a viable substitute. BTVS implies it's less effective. Forever knight is explicit it's less so.
The efficacy of animal blood is most likely going to depend on how difficult you want to make life for reluctant vampires.
In some settings, animal blood is just as physically nourishing but vampires who feed on it will become animalistic because they feed not simply on blood but the "lives" or "soul" in the blood (or a scifi technobabble equivalent).
In some settings, you may have vampires who kill their prey as a matter of principle and view taking non-lethal amounts as foul parasitism. Such as the Vampaneze in the
Darren Shawn books.
Sure they do. Serial killers manage it just fine. You just need to me mobile and have some idea how to spoof law enforcement putting the pieces together. Now, a whole coterie of vampires? Yeah, probably not, unless they're really mobile, but they aren't really rural anymore.
You may want to take cues from the True Knot in
Doctor Sleep. They're psychic vampires, but similar principles apply. In fact, it's much harder for them because they need to prey specifically on those rare individuals with psychic abilities. It's stated that all human beings have this "shining" to some degree, but presumably they'd need to kill far too many average people to stay unnoticed.