Here are my thoughts on your first 3 questions:
1. I've shot many airhsows and find I can't control exposure. The action happens so fast and different angles tracking planes - don't worry about it. If you focus on the arcraft you'll get the right exposure. Every hour is different as the sun moves, the light changes, clouds come and go and cover up the sun - it's too dynamic and you can't control this. Don't use a Pol-filter either. You'll get more keepers without any filter at all.
2. Tv mode for moving subjects - propellor planes use ~1/500 to 1/800 second to get prop movement. For jets use ~1/2000 - 1/4000 to freeze them. I use Av for stationary subjects to control depth of field. Adjust your ISO to control shutter speed. You may take a photo inside a transport jet ground display that is dark inside and crank up the ISO to 16000 or outside just need 100. For Tv shots I use 200 ISO to ensure I get 1/4000 for the solo jets at high speed
3. Al Servo - I always use it and you'll get more keepers, specially for autofocus needs. Take extra cards and fill them up. The key to focus points for me is using the AF Expansion With Selected Point custom function. Otherwise focus goes in and out tracking from the tail of the plane to wing of the plan next to it. Drives me nuts. If you use AF expansion the camera grabs all the planes and holds them steady and you get more sharp images that way.

I use a monopod - don't need to stand all day doing bicep curls with my camera everytime a plane flies by. I leave the testosterone for the younger folks. Some good advice already above from the other posters. I put some of my pics on a hobby website (http://straker27.smugmug.com/Airplanes) to show the pics I took using the settings above. Most of all have a great time - I'm jealous of your show center position. Will be at Mankato airshow this weekend - can't wait.