I think the hull deformation worry is overrated, as long as it was blocked properly. If it was stored indoors, it didn't have tons of snow piled onto it, overloading the jack stands.
Storing the boat out of the water lets the hull dry out, which is a good thing.
Yes, long periods of inactivity means that sealants and gaskets shrink and dry out. These should be inspected.
For the expense of $11,500, the boat should be surveyed. My Pearson 30 cost me $4,000 and wasn't quite as nice cosmetically, so I did not survey.
Something I noticed in the ad- The boat appears to have been re-powered with a Bukh diesel. They aren't necessarily "bad", but they aren't exactly common in the US, and parts can be expensive or difficult to find (as are some Volvo marine parts). Just something to consider. Try to get maintenance records for the engine, and find out how many hours are on it.
Bottom line: If the boat is as nice as in the photos, I think it could be a real gem. The Pearson 30 is a tough boat that sails well.