The way I deal with 1/2 is usually killing 1 or 2 of the giants off the bat, at which point I'll be surrounded, use SP to move away, and keep chipping. I don't worry too much about aggroing Ice Yendor, he's actually pretty tame. The main difficulty in 3 is sheer numbers; at some point I'll inevitably find myself in a corner or grabbed. Circling is a good strat though, I'll keep that in mind. It also sounds like you typically use speed-based builds, so maybe this is more a weakness of preferring strenght/intelligence builds than anything else.