yea they need to put a floor on where your rage can be reduced to, like you said. also, i like the idea of being able to use an ability in one stance and have it automatically change you into the stance that is required (like druids, as you said).
as far as arms mobility and survivability, i really dont know what they could possibly do to help that spec. i used to play arms and i had over 2200 in season 3 for a little while... and i only played pve fury as a side spec. i now only play pve, wether it be tanking or dpsing (i mostly dps) but arms warriors are underpowered for pvp. i really would rather play fury in a pvp environment.
what they COULD do, is just allow the use of rend and overpower in berserker stance... imo that would fix everything. i mean come on, dps warriors were meant to use berserker stance right? that would be a buff to arms and fury warriors though, i think.