If the guy only wants 300 for it, it probably isn't a clean title. Carfax doesn't receive all the reports on a car, just most of them. I would inspect the underbody and strut towers, hatch area where the spare tire is kept, etc.
As for the rest of your questions, I'll leave that to the more knowledgeable members. Welcome to NICO!

Got any pics of your current car? We LOVE pics.
