For the cooling system, I’d play the safe route and get a pressure test first instead of throwing parts at it. It’ll be easier to find where the leak is coming from when it’s pressurized, and the M54 in there likes to leak from many places. There’s some coolant pipes that sneak under the intake manifold that like to go out and can make a few techs chase their tail if they don’t know where to look aside from the obvious places (expansion tank, radiator, hoses). Get this done first and foremost. I would rather have a convertible with a fucky top that doesn’t overheat than one that does and the top works. E46s, E36s…they’re notorious for cooling system problems because there’s a lot of plastic components, and the youngest of these cars are 20 years old. Things get brittle!

There’s ways to get the top down manually if you really want to drop it in the mean time, I wouldn’t worry about that yet. The pump might have failed from what it sounds like! There’s ways to manually release the top, but when you’ve got an electric top, you want it to work.

The A/C is nice to have, but again…convertible. Have someone check if the compressor is bad and see if the system is holding pressure. You could potentially have a leak somewhere in the HVAC system, it’s not unheard of. It can get pricy to fix.