Whilst gender fluidity is entirely valid and 100% something I support, it is still ultimately the fluidity between two set sexes and I would consider anyone who's attracted to someone regardless of their gender as 'bisexual'.
As Dezzy said, its very definition just basically implies that anyone who identifies as a bisexual is inherently transphobic.
I don't really see the need for extra letters to LGBT because the very existence of an "LGBT" community is already fractured and complicated enough within itself - see every single example of gays rubbing trans the wrong way, the past ten years
Of course if it's just an umbrella term for "let's have a pride event, X Y and Z you're all welcome!" then sure, but I don't see any natural inclination for bisexual people to be associated, by definition, with say, asexuals, or allies. (I personally think including 'allies' at all is a bit laughable but that's neither here nor there).
Asexuality also seems an odd inclusion, since I would have thought having zero sexual interest wouldn't have much of an impact on your day to day life, and see little room for prejudice against you... save for a few awkward "well WHY don't you like sex!!!??" questions.
And once you start attempting to break down the differences between genderfluid, genderqueer, agender, you just generally start losing people and it's a little bit like trying to explain the rules to Quidditch to someone who's never read Harry Potter, nor has to.