So you can pick and choose if you are in the right school district.
Not trying to nit-pick here...but your statement contradicts itself. If it is at the school's discretion, then no, the parent/student does not get to pick and choose. The school gets to make the decision.
You said, YOu can't really choose to keep your kids out of the public school, and then pick and choose which programs you want them to participate in.
You said that you can't keep your kids out of public school...and I'm pointing out that some can.
BTW, I'm in this very situation. I'm trying to get a home schooled boy on our ice hockey team. Not sure where the school will come down on it, but the league is OK with it if the school district is.