I'm not aware of any RVs at YSU, I know there is at least one in Charlottetown. I spent a week in Summerside with my RV-9A last July. If you contact the airport manager Matt at
[email protected], you should be able to get some reasonably priced hangar space. I had a fair amount of brake repair work to do while I was there. I had a total right brake failure on rollout, I needed a tow back to the hangar which Matt was more than willing to help out with. Great people to deal with.
PEI is quite beautiful from the air, I managed a few family sightseeing flights in the area around the repairs. You won't find many airports on the island, there's only 2 (maybe 3) paved strips. If you come in during the day on a weekday, be sure to key up the UNICOM, they seem to monitor it well. YSU has a big runway, the hangars are at the north end quite a ways from the fuel. Fuel is only available (without callout) during the week daytime. Don't expect to find much more for services though.
As far as things to do and places to see, I can't suggest much. If you like seafood you should be happy. There are a number of dairy bars in the area, and beautiful beaches within an hour's drive.
Enjoy the visit, I wish I could go back next summer. Heck, maybe I will.