Keep a sharp eye out for any tears/cuts in the roof. Also, look for any splits in the caulk. While you're up there, look for cracked shrouds, missing/cracked/broken vent covers, large debris, and deterioration of the roof material itself. Also, look for spongy areas on the roof, indicating serious water damage or de-lamination (your roof is kind of like a wood-and-styrofoam sandwich). De-lamination, especially around the a/c unit, majorly reduces the structural integrity of your roof.
You mention that the camper is a 2006 model, purchased last fall. If you are not the original owner of the coach, your roof, and every other part of your coach no longer has a warranty.
When up on the roof, try to make sure to stay near the edges, or better yet stay on the ladder, moving it around as necessary, to do your inspection.