Did the vampire sleep with Albert's dad? Mmmm ok ok, weird but yeah

I don't think so?

I mean. It said his dad loved him too. Idk

As per author's notes, only Arden was Asha's 'past lover', Alberto (Albert's father) and that other female Blake only loved Asha, so I take no sexual relationship there, and Asha was calling Alberto creep and crazy, he was basically just asking to be turned into vampire and Ashe kicked him out quite early, when Alberto was still young, so I don't think there was anything sexual between them.
And it was confirmed that Albert is Arden's reincarnation, so Asha was only with him

I hope so. Maybe they'll tell us more in the side stories

That's the only option I can accept, seriously
I think we can take that as per author's notes and those connections in the family tree, only with Arden there is 'past lovers', with that woman and Alberto there's only an arrow that they 'loved' Asha, so yes, that's the only true I can believe in either way, love the reincarnation part, that Albert is basically Arden, and they are now together for eternity and author is not saying no for side stories, so there is a hope