As it's been said before, I agree: Role skills are a good idea, but shouldn't be limited in number, having access to all of them at once wouldn't be game breaking and would leave in the player's hand the choice to use them or not.

It's really bad when you are queuing for several instances at once, you don't have the required/optimal build for it and the tank pulls before you can change it, you end up with useless skills hanging around (Hello Esuna in Susano, I'm looking at you...).

While we are on topic: Making Repose a role skill could make some interesting boss fights where you could require the healer to put some adds to sleep.