1) The belt tensioner is probably shot.
2) I haven't seen oil pressure that low in an M119 and I looked at a few before getting the one I have. Not uncommon on M103s from what I've seen.
3) It has second gear start so it won't burn much rubber unless you mash it and engage first gear. You should be able to keep up with an 84 Corvette with second gear start.
4) If you're willing to travel and/or trust out of state dealers/sellers, you shouldn't have to pay $14.5K for a car in that condition.