yes, that's exactly the sort of overly-literal logic he is employing
It is discrimination, it's just ethical discrimination which is why nobody cares about it. Deciding who you do and do not want to have love with is ethical, disallowing people to marry is not.
It's not the lovees
Men can marry and women can marry, just men can't marry a man and a woman can't marry a woman. It is not loveism because both men and women have the same rights here.
I get what you're saying, but again as I've said before, it's not just one love we're talking about here. It's that both lovees are taken into account, it's still loveual discrimination, just based on two lovees instead of one. The definition most people recognize is when one love has a disadvantage over another, this proper definitions is "Discrimination based on love." It's more general.
Still, loveism does not logically work on both genders, because the definition implies that the other is discriminated differently, or not at all. But why would two men want to marry? loveuality, more often than not.
More often than not yes, but it's still got nothing to do with loveuality because no matter what their loveuality is, homoloveual, aloveual, anything, if they're the same gender they aren't allowed to marry.