Got solid ones in my E46 atm. Before that was meyle HD rubber ones.
Bushing refresh on E36 is pretty cheap parts wise probably $300-400 at a guess. I wouldn't bother inspecting them and just do them all at once when you got the funds. Add struts/shocks, links and mounts if not already done and then you good
Clear the Airbag fault and see if it comes back. Looks like an old stored coms code. If it was a concern your airbag light would be on.
Second stuff for emissions is pointless generic stuff. It doesn't mean any of the sensors have failed. You would need to check the live data for them and check if they are within tolerance.
"It is a convertible, and it is an automatic, it is not a race car." This is my mantra!
Plan for the car will be something similar to your setup, firm things up after almost thirty years.
My brother & sister in law both just let their regos lapse. I had been asking them are they on hold they keep saying yes but they must have thought that ment not keeping the old one upto date. 2 cars now sitting with dead plates, 1 was a beautiful e34 525i like the one out of the movie with the high speed car chase with Robert de Niro