I know, from asking Sims on dates, that the main requirement is 10 interactions with my date. When I get asked on a date, the requirements aren't shown, so I just make sure that I meet that main requirement, using Friendly of Funny interactions. I might also use Romantic interactions, but only if there's nobody nearby who might get jealous.
I didn't even know you could Present toddlers. I thought that was limited to Babies and Infants. Make sure that there's enough open space around the bassinet or crib, including an open space at the head.
Always Fly as a Bat means ALWAYS and I agree, that gets annoying when it's only a few steps. I usually don't use that setting. You can still make your vampire fly by clicking on the ground.