I'll go over some of this stuff with you tonight, but my basic tips:
If you're not in combat, get your knife out. You won't show up on enemy radar with the knife out. Especially important when taking down an empty zone or going after the enemy flag. This is not true. If the enemy can see you with their "characters" eyes, you'll show up on radar..
When fighting, lateral motion will always pay off more than forwards and back motion. It's harder to lock on to you, hit you with grenades, flamethrowers, etc.
The above goes doubly in a fight against a tank.
Always take the time to grab a weapon before jumping in a Warhawk or Tank. You never know when you're going to find yourself on foot in a firefight.
Don't toss grenades when in a fight with multiple teamates. Also be careful when in a tank.
Know the spawn points of all the weapons in your map. (this just takes time. When I first started playing, I'd start up a Lan game and just go around solo learning the maps).
If you're in a turret and you take a hit, jump out. A second shot is coming.
Proflight is really only effective in Dogfight games. Otherwise use normal fight to keep yourself oriented with the ground (it would be nice if you could switch between the two on the fly). Breesus doesn't use pro-flight. To each its own..
People tend to ignore chaff powerups in Warhawks. It's a good idea to always have the full loadout of 2 if you can.
You can only have 4 landmines down at one time. If you keep going and getting more and deploying them, you're first few will start to disappear.
If you're playing defense on CTF, try and keep one mine in your inventory to toss on a jeep or on the escape route you see the capturer taking.
Be aware of where there are usually mines and don't go charging in willy nilly.
If someone grabs a flag, grab a warhawk and give him air support. If no WH is available grab a jeep and follow. Nothing is worse than your flag carrier getting 2/3 home, dying and no one being around to pick it up and keep it moving.
When sniping, squat if you can. You're a smaller target and your name wont' show up when people are aiming at you, making you harder to spot.
Don't forget to move around when sniping. People you just killed will usually grab a rifle and try and find you. It's great picking them off from a second location while they search the spot you killed them from.
You don't need to worry about it in dogfights, but in regular game modes if you get in a fight with another warhawk, fire just a single swarm missile first to make him burn his chaff, then load up on him.
A jeep is much more effective with a second person in it.