I feel like we should be able to change gear mid fight as long as we are not changing classes mid fight, with no cooldowns.

E.g. as a Warrior I want to use DPS gear for the parts where I am not tanking and then hit a gear set to switch to my tank gear as I'm about to pick up an add or a boss.

I also feel that when we are a full premade, we should be able to change classes mid dungeon. Often times my friends and I que up and we want to do half the dungeon as tank and 3 dps, then have the 3rd dps switch back to heals. Or I might que on my Warrior and want to switch to paladin, etc. At the least we should be able to switch from Class A of Role 1 to Class B of Role 1. EG Warrior to Paladin, SCH to WHM, DRG to BLM, etc.