My main is a 70 mage, I leveled a pally + 4 shamans long after my mage was 70. For the past week I have been running stuff with pally+mage+3 shamans (one poor shaman has been abandoned) and its no problems.

I'm not exactly using all my mages abilities, I have a macro that is something like this (servers are down so can't tell you exactly):

#showtooltip
/stopmacro [channeling:Arcane Missiles]
/use 13
/use 14
/castsequence [target=focustarget,harm][] reset=combat/target Arcane Blast, Arcane Barrage, Arcane Missiles

Its on the same key as lightning bolt for shammies and consecrate for pally. Basically I just spam it all day until stuff dies, the other key I use is chain lightning on shamans (which casts Arcane Explosion on mage, kind of a waste usually lol).

Its by no means the most efficient use of my arcane mage, in fact I could probably get better macros if I went ice or frost (which I will do after level 75 probably) but I really enjoy arcane on my mage, especially solo.

I don't plan on sheeping anything ever, afaik you don't need any CC really in any of the 5 mans or heroics in WOTLK. Heck there are people who are 2 manning the first instance.