Homosexual is attraction to the same gender; heterosexual is attraction to a different gender. The bi in bisexual is both of these, not attraction to two genders. Think of the bi flag, pink, purple, and blue: what do you think the colors represent? Nonbinary people have always been included in bisexual if you take some time to think about.

Read the bisexual manifesto. Bi has always included nonbinary people. If you are attracted to all genders, both bisexual and pansexual are valid labels you can choose.

Yes it does. Read the bisexual manifesto.

I say this as a bi person, not a straight

Pansexual, polysexual, and omnisexual are all microlabels and are all subsets of bisexual. You don’t need more labels than gay, straight, and bi.

Edit: I forgot about asexuals. But I specifically only care about bi subsets. They’re dumb, and you only need bi