I'm still learning how to get the most out of my D800 and haven't done many airshows recently, but here's some things to think about.
You many want to use a lighter lens (maybe your 70-300). Carrying the BigMa around for a day is going to be very tiring. The D800 has enough resolution to deal with the shorter reach.
I know it's stating the obvious, but with all that available resolution, the D800 can expose less-than-stellar panning technique as motion blur. Faster shutter speeds can help.
Use shutter (or manual) mode, and set the shutter speed to allow an appropriate amount of prop motion, while minimizing the potential for (non-prop) motion blur. For prop blur, I've had reasonable results using 1/100th or 1/125th second exposure. For fast moving jets, try 1/300th or faster.
I'd stick with RAW, but that's mostly a personal preference.
Here's some non-D800 specific considerations;
Unless you're photographing the static display, forget using a tripod. I find a tripod more of a hindrance than a help. That said, a tripod positioned to photograph the runway could be a great place to park the BigMa when you're resting your arms between displays.
Pay attention to background. A large amount of plain blue sky adds little to enhance an image (I know that's a rarity in the UK, but you can always hope). Similarly with take-off/landings, the background can add unnecessary clutter.
With a little forethought, the D800 will give you some great images.
I'm sure you'll get a lot of (much better) advice from the Aviation forum people, so I'd recommend asking your question there too.
What airshow are you going to? I used to live in your neck of the woods, and (back in the day) was a regular attendee of Farnborough and International Air Tattoo.