Wow.. So many questions! Probably the best way to get the answers would be to go to the Informational Meeting and Tryouts, talk to Nelson or the other coaches, and see if its a good fit for you.
And speaking from experience, Motions is an AMAZING program to be a part of!
For those of you inquiring about the coed team, all I can say is be one of the best the day of tryouts. I can't say for certain what skills are required. Maybe it will be a standing double full, maybe all you have to be able to do is breathe for 2 minutes and 30 seconds...but if you are one of the top 35 kids that day and you fit the age group, you got a good shot.
If you're wondering about size, just tryout. If it turns out you don't like it, don't come to the first practice.
I hope that helps all. Alison is right, Motions is an amazing place to be!