Instant-mount summoning would be very nice, eypecially with internet that's somewhat slow sometimes, but not all the time. So sometimes I can start running again when the cast is almost full without it interrupting, and someimes it gets interrupted when I run as soon as it's finished and i have to summon it again.
As for the other two, I'm a main whm so TP doesn't really affect me, and the floating mount would wurely be nice! I think I saw someone sugesting it somewhere before, but I cannot remember for sure.