You give a group fewer rights, without a logical rational reason, and that group is oppressed. Yes, that applies also if the group is gay, even if you don't personally like gays.
Why is that?
If a group has fewer rights, they are victims. They may need money to fight for their cause, because that is the kind of society we live in.
But if there is no logical reason why I can't be called a diplomat, I should be called a diplomat.
Human constructed, changed by humans, as I said. The same argument was tried against inter-racial couples, that they could marry someone from their own race, and didn't meet the current definition. This is just a way to stop all debate.
No, it is not. Extremely few animal species even attempt monogamy.
Why do you say that? Is it because they are not heterosexual? Non-heterosexual activity does take place among species in nature, and also among humans, which are also a part of nature. How we recognize, is a human construct, whether it is gay or straight.