Thanks for that, the situation seems to have been pretty much unchanged from my time (though the Jordanians etc weren't present then). If I may, I would just offer the following:
1. There was a Major Incident Plan in place in 2010 (I wrote the Aircraft Accident Annex). Certainly my Annex was a joint document and we table topped various scenarios with the USMC. I even had a Marine Capt liaison officer working for me in Air Ops.
2. Contractor security and vetting was always a problem and one which nobody really wanted to grip. It reached farcical proportions when an attempt was made to get Air Traffic Control to vet them and issue an Air Side permit, on the principle they had to drive around the airfield to get to the construction site. ATC was promptly inundated by thousands of applications, most of whom could not speak English. We eventually got this turned off but it was not satisfactorily resolved during my stint.
3. The Jan 11 MOU essentially formalised the status quo. Leatherneck and Shorabak were essentially separate, self contained, autonomous camps. I suspect that the greatest level of cooperation was on the ATC / Airfield Ops side (which worked very well).
As always, my comments are caveated that I am a mere Ops Wallah and not a FP guru.