Ugh, yeah, it's a complicated mess. The latter two are presumably not a factor in Alternity (I think it was mentioned in Y1 that Harry had some Parseltongue, but it didn't come naturally to him--he had to learn it)

The first, though, we don't know about. And I could see its presence ending up being a factor, if it exists. Or it could not come up at all. It's hard to tell.