Thanks for the insights folks. Objectively, i am doing it wrong, as i'm putting too much faith in the mercs abilities to keep group alive and not enough faith in myself as a player and my own ability to heal, tank, dps, etc. I'll try a few variations of my teams and see which gives me better luck in the xp/killing department. Also, thanks for the tip on modifying the ini.'s, i actually have done some tweaking like adding Snare instead of X on my druid or Root on my wizzy vs. Y, as well as modifying med percent and what not. I'll keep experimenting and reading this forum -- worst case scenario i re-roll some toons and try again
The rule is always to play what you want as long as you're having fun, but it doesn't sound like your having a lot of fun right now. So I'll just give a few thoughts on class lineup.
I see that you mention both wizzy and druid. I don't want to set off a class war, but both of those classes are really weak in the early game. They are super mana dependent in an era where mana regen sucks. They get better later, but they are a total drag on exp groups at your level.
Melee classes really excel in the low levels because they don't use a lot of endurance. They can basically fight forever and put out consistent dps fight after fight. Rogues and monks are excellent choices because all they need are decent weapons.
I prefer bards over enchanters at low levels for the same reasons. Even though they don't get an AoE mez, nothing they use at this level costs any mana, so they can do it forever. They also match up really well with melee toons because of haste and overhaste, which you'll start getting in your 50s. They also bring some good pulling tools which you sometimes need at lower levels (at higher levels you just pull everything and let the CC sort it out).
SKs and Paladins are really mana dependent early game, but they get amazing later in the game. You could switch the SK for a warrior, but warriors have terrible aggro at the low level, so you're trading one thing for another. I'd say just play whatever you want for the tank. There really isn't a perfect answer, but all three are viable.
Clerics are really the only option for heals at this level. But the only efficient way to heal at the low level is with complete heal. Unfortunately, it's almost impossible to really automate a 10 second heal. What I do at the low level is run
mq2cleric in paused mode. I have hotkeys to cast complete on my tank and the highest group heal when needed. This lets me control it's mana usage during xp runs. On boss fights or whenever shit hits the fan, I just unpause the plugin and let it blow it's mana because I know it will keep everyone alive.
Finally, mercs are really bad. You can make an argument for using a tank merc early game because they can carry a group, but the healer and dps mercs are really bad and only get worse as you level up. I'd just ditch those mercs altogether and figure out what group works for you.