There are a couple of people who do plug and play options. If you go on the facebook group, most of them are on there, put a shout out and I'm sure someone will come to you.
And the air con was a rather large ball ache, but ultimately worth it. Was lovely driving around this summer with the windows up!
Afraid not, this was the birthplace of ECUs and interrogating them wasn't brought in till the mk3 platform. Some G60s have a very rudimentary form of diagnostics, but to my knowledge, the normal 8vs never got it.
Might want to look into that one! I highly doubt it's never been done, but definitely pop off the cover and have a look. See if you can manually wind the engine over until you can see some markings on the belt. If it's VW marked/there is none and the belt looks worn, the chances are you could be on a wing and a prayer!
Generally speaking, whenever I get a car, I'll swap out the belt if I've got no history/evidence of it being done recently. For the hundred or so it costs, it's well worth it for piece of mind.
So one way to check the pump is to pull the dizzy out and manually drive the pump (as the dizzy also turns the pump drive shaft). I've primed one before by sticking a drill on an adaptor (can't remember exactly what type, but have a feeling a large flat head will do the trick) and spinning it up until I could see oil getting everywhere, a good way to do this is pull the head oil temp sensor and wait for it to come out.
That being said, oil pumps aren't expensive and while they're still available, you may as well chuck one on for piece of mind.