1. Stick to Abyssal Drain over Unleash unless your MP is low.
2. Red Mages in particular seem to have an unhealthy obsession with trying to pull off the tank. Give them what they want: Shirk them until they learn to properly use Diversion and Lucid Dreaming.
3. Related, but a lot of tanks are still of the mindset where they can sit out of tank stance all day. Don't do it. Not without a team you can trust to know how to handle their enmity.
4. Tenacity is kinda crap right now, seems to have the same scaling as Parry. It's not as bad as Parry, given that it's not RNG and is doing two things, but it's still crap. Direct Hit melds are your friend right now.