Do really well in school.
Find yourself as many leadership and teamwork opportunities as possible.
Stay away from drugs or legal trouble.
Learn everything you can about the trades you are interested in.
Work really hard on everything you write/turn in as part of your application.
Practice interview techniques, and get as familiar as you can with the CF interview. Somewhere on the internet there is a pretty good preparation guide. If I happen to see it, I'll post a link.
Other than that, your post says pretty much "I'm really good at x and y, not sure how to improve z, what are my chances of getting in and how do I make them better?" If you take some time to look around, you'll find that your post is nearly identical to 42523956495813115 other ones on this site where people are trying to get a feel for their odds of success in the selection process.
Nobody here can tell you what the odds are without having access to every bit of information regarding every applicant for ROTP this year. You'll be given a numerical score based on the quality of your application package, which includes tests/interviews/etc., and if that score is higher, your odds are better. If everyone else's scores are higher than yours, then your odds are pretty bad.
It's all relative. The spots go to the top scorers.
Good luck.