4. is it acceptable to ground taxi,sit loading pax and refueling with the AFCS engaged
As far as I am aware there is no requirement to disengage the AFCS on the ground in the S61 (Matelot99 appears to have been referring to Sea King ?? which presumably may have different SOP's ??).
I flew S61's for Bristow years ago and they definitely didn't require AFCS disengaged on each landing, or while taxiing - it was one of the things I had to get used to doing when I converted onto the AS332. I now fly S61 for British International, and have just been through the books to make sure I had not missed something, and am sure that here we also are not required to routinely disengage AFCS while on the ground. The only exception is when we have landed on a moving deck. Other than that, ours goes on before first take-off and stays on till just before shutting down.