Manual mode, auto ISO 100-3200, AIServo.
Customs functions: C.fn III-2 set to slow, C.fn III-3 set to 3: release / tracking priority. C.fn III-4 set to 1 continuous AF track priority. C.fn III-8 single point expansion with 1 maybe 2 so you get some expansion off your single AF point but don't go with all of the AF points. I would start using the center AF point it's way more sensitive then the rest.
If the 70-200 is hunting switch on the focus distance limiter on the lens, if it still hunts set C.fn III-5 to 1 and see if that helps. You might need to prefocus the lens though if you set that.
If you're shooting jpegs check your noise reduction settings, that might be messing with the sharpness at higher ISO.
Send me some pics from your shoot so I can see what you got going on.