Unfortunately you're gonna have to learn to live with these things.

I've been there though like most of the others so I understand, one day I want to sell it, the next day I don't. Luckily I'm currently going through a keep it phase

I would say join the AA (up to 25% off if you join online, thats what I did) and buy yourself a cheap runaround for daily use. Keep the RS if its making you happy.

At the end of the day 99% of the time you will not make any money from a car, you will just throw money at it that you won't get back. It's the same for any car. Having a retro car as a hobby means just that, you have to be prepared for it to have an effect on your bank balance. However, if the enjoyment it gives you outweighs that then it's worth it

The things you've described don't seem to serious, if you've not got a Haynes manual then buy yourself one and get your hands dirty, they aren't too hard to tinker around with. Plus there is a huge selection of new and 2nd hand parts for these cars on EBay.

Good luck