Rectifying a few small issues..

[X5UK88]

I'm hoping to sort out a few annoying bits on my X5..

1. Parking sensors aren't working, I've listened for clicking, all click except the inner 2 sensors on the front bumper. Are these likely to both be faulty or could it be something more?

2. Self level suspension fault shows on dash, as far as I'm aware the suspension just stays as is. I believe it lost all air from the rear with the last owner, but they managed to get it back up and it's stayed there but doesn't work as it should. Any ideas where I should look first?

3. I get the tyre pressure controls inactive message, this is really annoying. Anyway to get rid of this without fixing the issue? If not, what should I be looking at?

If anyone can offer any input it would be appreciated.