Wailing Caverns clear.

Placed the group in Dalaran to have easy access to class- and profession-trainers.
I'll only level via LFG and when I'm rested.

Switched to 4 Shadow Priests, one of them with stopcasting and healing macros for my tank.
Simple basic castsequence rotation of shadow word pain and mindflay with [nochanneling]
so I can spam it - works excellent.

revived my old fun-group of 3 warlocks (thanks to Andreauk) for questing and fun
outside of instances while my main group is resting.