Play around with this macro, and you might be able to recreate what I have done.
It will bug out your broom mount, you will still have the "Flying Broom" aura...But you won't be seen to have the broom actually under you. You can jump, and swim around in the air. No, it isnt client-side. Other players ask "how are you swimming in the air?" "omghacker reported"...shit like that.
/use noggenfogger elixir
/use magic broom
/cancelaura noggenfogger elixir
Spam it, while jumping. Hit the macro, and then jump instantly afterwords. Other shit happens, like sometimes you will just end up floating in the air, stationary. Basically, just edit in all your /use items and skills that don't share a cooldown. And spam the **** out of the macro.
Add other "use:" items. Like Don Carlos' Famous Hat, Other vanity pets, other skills, etc...Use other commands like /equip and so forth. I use this:
/use noggenfogger elixir
/use magic broom
/use Don Carlos' Famous Hat
/use sandals of summer
/cancelaura noggenfogger elixir
Good luck, you will really have to play around with it. But, I got it to work...Let me know how it goes.
Also, play around with the /cancelaura. I can do some other neat things with it, it takes quite a bit of trial and error macro writing.
For example.
/cast aspect of the hawk
/cancelaura aspect of the hawk
Spamming that makes the animation for aspect of the hawk appear, almost constantly.