I think that the Vampire Lore skill is two-sided. Whether or not your sims become vampire food is a mix of pot luck and player action, but that skill makes vampires more likely to bite your sim. It also helps them learn defence techniques and defend themselves too though, and unlocks a lot of cool features. In under five hours real time, you can max all fifteen levels of it. Level eight is about halfway through it so should
Also, to avoid sims passing out everywhere, grow a garlic plant. Garlic seems super common in game and some vampires (including Vlad) seem to hate it. Track down a bulb of garlic, plant it in the ground, look after it, and reap your results. You should get a lot of garlic every week from it. Place some garlic along the entrance to your house and the land leading up to it. Add more to your house when you can.
