Too bad it didn't turn out to be a perfect deal. A couple of thoughts.
Like Andy said, do your best not to be intimidated by all the running and standing rigging. That's something you'll get used to in pretty short order, and it becomes second nature.
Regarding the cracks on the centerboard trunk. If it's spiderweb cracks in just the gel coat, they may not even need attention. If it's cracks in the fiberglass, you may have something that ranges from a relatively simple fix (at least for someone with glassing experience) to a deal-breaking structural problem. Without looking at it, it's difficult to say.
Finally, though, the trailer sounds genuinely problematic. If it's not built for the boat, launching and retrieving could be a pain. But more important, you don't want the boat bouncing around and getting stressed when you transport it ... that could do serious damage to the hull. If you're handy, you might be able to deal with it, but you might be better served continuing to look for another boat. There are lots of 14 to 18-ft. sailboats out there.