Hey, NYRedNeck, Im also turning 35 (Yikes!) in late August. Unfortunately, I wont be celebrating at the World because I cant take off from work that time of year. So have fun enough for the both of us.
My absolute favorite restaurant at WDW is Boma at AKL. It might be challenging to get to if you dont have a car, but the food is amazing, and we love the relaxing atmosphere at AKL. I think it would be good for a solo diner, because it seemed to me all the smaller tables were more isolated in the back of the dining room (kitchen is behind the buffet, bathrooms are outside the restaurant), and some have nice views of the landscaping outside. These would be further away from the food, but its worth it to me to walk to get my food, and not have people bumping into my chair. I think a buffet would be good for a solo, because you can get up for more food as you want without worrying about disrupting your table mates.
When DH and I were there in November for our anniversary, we had ADR for the first seating, I think at 4:30. We asked for and got a table by the window. Our great server, Shannon, noticed our anniversary buttons. I told her I loved the coconut tiramisu. She said it wasnt on the buffet that night, but shed see if they had some in the kitchen. She had the pastry chef whip up a beautiful presentation of it, with Happy Anniversary and a hidden Mickey scrolled out in chocolate. It was so beautiful, we took a picture, then practically licked the plate clean. I cant promise youll get this treatment, but if you wear your Happy Birthday button, it might help. By the way, if I were you, Id get a b-day button as soon as you get to your first park and wear it all week. I think 35 deserves a little extra celebration.
Sorry for the long post, I just get too excited thinking about Boma. Hope you have a great trip!