I'll take your examples for response..

The players before a game? Tough call. It's supposed to be about teamwork but the Jewish kid is left out of that. Until said kid starts getting harassed, though, it's a gray area that might do well to consider another solution (see *)

The money? It says God (common to almost every religion), not "Jesus our Lord and Savior" (much more specific). I don't have a problem with that.

Congress starting with a prayer - is it forced participation? In addition, it's not a law.

The USSC? I think one of the jsutices would have to challenge that as other don't have legal standing.

The Pledge? "Under God" was added in 1954 in reaction to the "godless communist" threat.

Vouchers for religious schools? I'm kinda neutral there so long as religious indoctrination isn't part of the curriculum.

As far as leading in a voluntary prayer, it saddens me that the solution isn't self-evident. I moved to NH in 1974. The school day was started, after the announcements over the PA with a "moment for silent meditation". If you wanted to pray, you could. If you didn't want to, that was fine. Everbody happy.