13-16 for raw files? That is impressive, and I wouldn't have guessed that.
Also remember to double check your camera is in its continuous tracking mode for the focus. (AI Servo on Canons, but I think Nikon calls it something different.) Really sucks to come back and find you've been shooting in oneshot focus for part of the day.
If you haven't tried it already, I suggest giving back button focus a shot, assuming the body supports it. A lot of shooters find it more comfortable to shoot with and hold focus instead of half pressing the shutter, and it ties in very well with AI Servo focus. (Enables basically one-shot and AI-S at the same time. Just release the focus button and it won't refocus when you take the next photo)
Don't know what style mask you wear, but I personally find that a single curve lens in the mask is a little easier to use than a bi-curve/bubble mask. You're not going to get a great view through the eye piece, and when I first started shooting with a mask on I found it extremely easy to get totally lost as far as my sight through the view finder went. The vertical lens in my older VForce Vantage made it a little easier to keep alignment than the double curve of my Grills.
Don't know how others normally shoot, but personally I got into the habit of shooting with both eyes open, and aiming almost as much with my left eye down the barrel of the lens as I did with my right eye through the view finder. I keep the framing sloppy and crop in post.
Also, now I really wish I was getting out to the field here soon, but sadly it looks like I'm doing landscaping around the house tomorrow.
I haven't shot paintball with my 7D yet.