sounds like most of the basics have been covered already.
The best advice i can give, think it was mentioned already though, is to have fun.
Also, take a camera and post tons of pics, we like action shots and "kill cams"
also, make sure that you know your marker in and out, i cant count how many times i have had some issue that required field stripping my marker in a firefight. (not fun, btw. lol) bring rags to clean your gear when you are off the field. if you can, get extra o-rings for our markers and an extra lense for your mask, just in case....
the other important thing ive learned from long scenario games,wear comfortable shoes.
good luck with the game, let us know how it turns out.