You're not exactly looking for trouble, but any old boat can certainly dish out more than its share. You need a survey, and you need to go in with your eyes open about all the things - big things and "little" things - that need attention. Once you have a full punch list of what needs to be done, you can weigh that against your budget, both time and money, and come up with a value. If the seller agrees, that's it. If not, move on to the next one.
A gen set is not required. A lot of people find that a Honda 2000 is enough to top off the house bank or heat the water or cook a meal, whatever. I'd probably run mine if I absolutely needed the Air Conditioner all night; my built-in gen set is a bit of a tooth rattler. Some dummy bolted it right to a board that's bolted right to the stringers.