I'm not single, but DH is not a huge WDW fan, so I have taken DS11 on dozens of mommy/son solo trips since he was 3. We LOVE them! We have our own special traditions in the parks and we have such a great time together. If he is nervous about the coasters, don't sweat it. There are SO many things to do in WDW. My DS used to be afraid of the coasters, so I started him out on Barnstormer, then 7DMT and then Big Thunder. If he doesn't want to do them, I wouldn't push it. If he likes interactive activities, DS loves the pirate adventure, Sorcerer's of the Magic Kingdom, Wilderness Explorers, etc. He also loves the water parks (BB in particular), mini-golf and going to the Boardwalk at night. When he was 8, I could barely get him out of the Japan pavilion in EP because he liked Pokemon so much. I would just go at his speed and enjoy whatever he seems interested in at this age. I love solo mommy/child trips!