[Lifebar]

When I was leveling up I would keep my lowest level root and lowest level stun memmed all of the time.

The root is not great, but it's VERY cheap, casts fast, and is really not much worse than any of our other roots pre-paralyzing earth. It can help the group a ton, and if you position them away from the group, you're essentially turning off the damage from non-casters for as long as you can keep them rooted. I have used this to great effect at all levels. When the chanter's pet breaks as a 5-pull arrives at camp you can start parking them while he recovers.

Stun is cheap, fast to cast, and nice for interrupting casters--but it's even better for getting mobs rooted away from the rest of the group. If you have an add that is not being cc'd just stun it from across the room and sit. As soon as the ultra-short duration stun breaks and it starts running at you--cast root. You can get it locked down away from the group, usually without taking any damage yourself. Is it a caster? Do the same thing but run it around a corner and root it out of line-of-sight so it can't cast on anyone. Note: when root breaks it will still be coming for you...but just re-root with cheap roots =)

At 60 I find that I need to root less frequently. Most of my non-healing at this point is stunning (with the same minimum level stun) to interrupt casters, and stripping damage shields with Mark of Karn or Cancel Magic depending on how resistant the mobs are, how many melee need HP, etc.

Also as Estu mentioned lulling / pacifying is totally possible. Add some CHA gear in to help avoid agro from critical resists if it's something you plan on doing often or in very dangerous places (i.e. pacifying through Sebilis).

If you're having trouble with your mana pool, check out the wiki and look at equipment by class by slot. You can get a boatload of WIS pretty cheap these days. There is a lot of good, transitional gear available from 25p-200p per item in EC. Just chart out cheap pieces and save up for each one in order of mana per platinum.

Good luck and go Clerics!