Yeah, I have problems with #2 too. Can't see my dynamic heading pip on takeoff because it's too high, and heading tape is like 1/4 of the way up the HUD.
I have VR recenter keybound so I can fix it. To "adjust the seat" for A2A I sit up really high, hit recenter, then sit back to regular position; I sit up a little high and hit recenter for A2G/takeoff/landing.
It's dumb, but FC3 doesn't really seem to get any love, especially the A-10A since there's a hi-fidelity alternative.