I must say it's odd that stateside they don't consider you to be in command of the helicopter whilst stationary - otherwise, who is? in the event of an incident? I'm not sure what goes on in the GOM but is there really that much time spent stationary, blades turning? Sounds like you should shut down and have a cup of tea if the difference between engine running time, and flight time is 4 hrs
Depends.... One can log time form the time the aircraft first moves under its own power till the time it stops. Therefore, if you hot re-fuel then you can log all the time.
You'll have to do a very slow taxi whilst getting refuelled so as not to stop moving!