If you find yourself in the MT group a lot, you should make sure you have Geotic Brand adept 3 or better. That is the group buff that is adding all the sta, hp, and a very nice chunk of mitigation to the tank. When I am in the MT group, I usually toss out a volatile haven at least once every two times it recycles as well. Geotic Brand is the real key though since the mitigation it adds is essentially equal to what the MT gains from a full group of buffs normally.
For mobs that do not have an AE, and especially mobs that are weak against crushing damage the best place for a conjuror is in a group with lots and lots of haste. Coercer, troubador, dirge, and inquisitor all have group haste that will thus affect your pet and the aqueous hunters. I beleive the ideal group for a conjuror would be: Conjuror, coercer, inquisitor, dirge, and then the last two slots for other classes that have group procs of some sort, or more likely a couple scouts to reap the benefits of the previous four classes.