On the 7D, it's C.Fn IV-1 which controls all assignments of functions to buttons.
For action, I set it like this:
- Single point AF with expansion.
- Servo AF.
- Joystick to immediately move start point for AF.
- Metering: Center weighted if using AE, otherwise partial.
- Trigger button: Metering only
- AF-ON: Focusing while pressed on selected AF point.
- *: Focusing while pressed on registered (HP) AF point.
- Orientation dependent AF point selection. This is true for the HP as well.
- M-Fn: AE lock, should that be needed.
- DOF preview: Modifications to AF tracking and interference handling, plus siwtch to Zone AF, if the subject comes too close to handle well with single point expanded AF.
To use automatic exposure or manual is something I decide upon depending upon the conditions. My subjects are usually on the ground, among bushes, trees, other people, shadows and sunlit areas, so both focusing and exposure is sometimes a bit too variable to be easy to handle...
The Home Point I store so that it's high up in the image. Thus I can always focus on a face, if I want to, by just using the * button instead of the AF-ON. The main point is often in the center, but I move it around as needed. These setups I store under the C1 and C2 locations on the mode dial. Very handy.