I think you guys are thinking too much of the game. I'm basing the RP more on reality than anything. There won't be a squad of 6 soldiers. I believe I've mentioned this before, but the initial size of XCOM (Or UNXIPU) will be 4 squads of 10, though they won't all be deployed at once, and neither will an entire squad be deployed all the time. It depends on the situations I guess.

XCOM will never be alone either, as this is a game concerning the world. I won't spoil too much for you guys :D. For starters, XCOM/UNXIPU itself consists of numerous departments, and even scientists and engineers might take to the field if the situation requires it. XCOM has a security department too, so you might find them around your characters in places other than behind a desk, drinking a mug of coffee. Then there's the various law enforcement, paramilitary, military and international organisations that might/will get involved.

Technological advancements are a guarantee in the RP, though how far will we go, I'm not sure. I want the RP to be as freeform as possible.

There's another thing I thought about... Which is to divide the RP into seasons. Once enough progress in the story has been made, a season will end and a new one will eventually begin... With or without players and characters from the previous seasons. Characters that get left behind will, of course, ultimately be traceable, and they could be anywhere between being transferred to being retired or killed. They could come back out of the blue too. What do you guys think?