My semi-old, pushing maximum density friend...looks like the ECNL teams play conference and cross-conference schedules, along with National Showcase tournaments thrown in at various times.
The KCFC United U15 girls are scheduled to start playing some conference games in the Midwest league here in Febuary.
High School ball is definitely lacking in quality and skill of most teams and players, but High School ball, as I've always seen it is for the players to play for their school and pride. Totally different atmosphere and surroundings for the players to play within. It's kind of like stepping away from the seriousness and rigor's of club ball and having some fun playing soccer with high school friends in front of your peers. I see the good and bad of it.