As someone who has no experience of sports being governed by such rules (from Ireland) at the risk of appearing stupid may I ask to what end these rules are introduced?? I am guessing that perhaps it is to protect students from over zealous coaches that wish to train year round etc. but that said, why does this have a bearing on when a coach can start coaching ball skills - the most basic fundamental of the game, and sadly what you Americans are most lacking in at every level right up to your National team. A kid who wants to learn should always be given the opportunity regardless.
Sine le meas
Af
PS - regarding fitness, conditioning and ball skills, you can make a player fit over a period of say 2 months - soccer skills however....are something you never stop learing right up to the day you retire from it.