Is there any chance of having a couple more roles added to the list?
One that I'd be interested in is a dedicated artillery gunner - obviously still following the same ROE as the FOB gun and CAS, but as a legitimate role with more ammunition. I've lost count of the amount of times I've gone to use the gun to support various actions and found that somebody has just pissed all of the rounds away somewhere and the gun is spent. Perhaps if it were an actual role, people might be inclined to use it more sparingly and responsibly.
Another potential that came to mind recently is a dedicated commander role - basically along the lines of the commander role in Battlefield 2 (If anyone actually remembers that relic). Pretty much just a non-combat position coordinating ground action, air and artillery support