Your mileage could probably vary depending what you're running... But I'm kind of thinking, "Oh kill some off one by one, starting with the most apparent cpu hog. What's the worst that can happen. You nix the wrong one and have to restart?" But yes, at least you can see what's hogging memory in task manager.
I used to have a comp where one memory hog process (around 20-30%) with that name always came on at startup -- I didn't know exactly what was behind it either, but I'd promptly kill it off at each start from task manager, and it was never a problem afterward there.
That might just work out to speed you up, until you figure it out more permanently (it sounds like you're restarting a lot as is, so maybe not a big loss if it takes a couple attempts). Of course, with friends like these if you're lucky, maybe you can name the culprit behind the mask and directly prune the bugger as well