Dog....if you include questions # 2 & # 3 from Clark's list...you'll be my hero.
Regarding "Challenger"....I wonder if those are more local tournaments (in Texas we call them Grand Prix tournaments). Designed for kids wanting to get some tournament play without worrying about Sectional points.
My kid played in 6-8 "Grand Prix" tournaments when he was 9. They were great intermediate tournaments for him allowing him to get more "tournament tough" prior to competing in our Section's ranking tournaments.
Two other thoughts:
- Call the local USTA (St. Louis?) office.
- Ask the parents of a really good (ranked) 12 y/o (in St. Louis) what the drill is....they will have already run the gauntlet.