We're also sailing on the 7th for my daughter's 13th birthday. It will be our 10th trip on the Magic, I think it is the 3rd or 4th Eastern cruise. We'll do a week at Dis World also.... The big thing is that she can't wait to be allowed into the TEEN program.
I really don't think the soda thing is worth the money. You get pop free at all meals (in the sit down restaurants), and really don't "need" it in between. You can always get iced tea, milk, lemonade, fruit punch, hot chocolate free.
We frequently do this week because of the birthday. The weather can be anything from 85 and wonderful to much cooler...we've only hit one cool week on the Magic, but it has happened several times at DW. There's just no way to predict. If you're doing any park time, bring at least one long sleeved outfit.
Palo reservations do fill quickly, but they also have "no-shows." Make your reservation as soon as you get on the ship. Then, if you can't get a reservation, get on the wait list and keep checking. Even the evening you want, someone may be a no-show and you might get in.
The reason our cruise has increased in price is that it is getting more full. Disney has a system of controlling prices based on how full a cruise is and the length of time till the sailing. They just adjust the "early booking" discount.
My experience with the kid programs has been generally good. If my DD makes a friend, then she loves the programs. If she fails to hook up with a buddy (or the worst case, she and another girl made friends, then the girl was told that she had to hang with her cousins, not a stranger), I start to hear that the programs are "boring." That translates "I don't have a good friend there." We always travel "off season" (except the first time) and have never had a problem with over-crowding in the school aged programs.
I'm game to field any questions that I might be able to answer. In general, we've sailed on the Magic twice a year since the inaugural sail. We sailed on 2 other ships previously....and Disney has them all beat!
Kathryn