Thats what is done on RC Heli's, the rate gyro directly sums into the
normal command. The only control you have is the gain on the gyro and
I'd guess you'd have to adjust this to particular aircraft and
preference of the pilot.

I assume the gyro(s) would be pretty near the center of motion along
with the pilot, but why is this a requirement? Doesn't any ridged part
of the aircraft experience the same yaw,pitch,roll accelerations? One
possible implimentation could be a gryo co-located with the actuator
(servo) that controls that axis.

I think this would replace manual trim because if you could do the
stability control, you sure as heck could make it move back and forth
in response to a 3 position toggle switch.

If it breaks you fly without trim till you land. I think there is some
rule that the aircraft must be controllable with any trim to it's full
limit.