Is founding a varsity sports team for your high school and managing the program (fundraising, recruiting, scheduling, etc) a good EC?
ECS are just filler --they are generally almost meaningless. Schools want to see that you things besides schoolwork (well roundedness) and if your non academic activities are particularly time consuming then it does add to you academics in that it may explain grades that are imperfect or really show you are a handling a heavy load of work and ECs --its just fluff most of the time. No EC is a bad Ec unless its fake
Yes. It shows leadership and initiative.