"Queer" fits in people who aren't homo or biloveual. It's only redundant if you have A and P in there, which LGBT doesn't.
Neither do I, but you have to use the correct jargon to communicate to people correctly.
biloveual is often just used for two or more, despite the word itself being more strict, so A could be added to the end in place of QPA or whatever, and it would be fine
but redundant or not, it isn't okay to use a slur as an umbrella term, even if some people under that umbrella are okay with it