I haven't play vampires long enough to have the age thing be a problem. I understand how that could become weird, but I kind of like that aspect of vampires. I've been wanting to create a coven of vampires who live with some humans and see how that plays out. I've played Caleb Vatore the most of all my vampires so far and he has two twin daughters, one a vampire and one a human. Their mother was human when she got pregnant, then became a vampire, decided she didn't want to live forever as a vampire and took the cure. I'm still kind of figuring it out myself.
You could definitely have a save where you don't allow vampires to have babies naturally. The only vampires that get to exist are the ones who are turned. I've thought about doing that as well. Then if your vamps wanted to have children they would have to adopt.