Check out the rover 75 and ZT club forums.
There's a t piece you can get which can help prevent the issue with the head gasket I believe.

The handbrake compensator stretches causing a poor hand brake, but it also depends what options the car has, such as the driver intelligence pack which includes rain sensor, reverse parking sensors (both bmw) and obc. They go pixelated with age and are impossible to repair.
Also, depending on age, if the a/c doesn't work it may be because of the radiator fan failing, rather than an issue with anything else.

I had the diesel one which comes with it's own issues. Egr, maf, clutch / dmf issues, injector issues.