I feel for you and your son. I've followed a lot of your posts with interest because my kid is a keeper as well. We need a GK Parent Union!
Like SoCal United said, this just basically puts you into good company with all the rest of us. I don't know anyone who just had a sweetheart walk all the way through club soccer. Most people suffer the drama early and have it smooth out over time. It's actually better this way than to have an easy ride early and then have this sort of drama later. I know kids who are Jr/Sr in HS whose club teams disintegrated at the last moment and that is very disruptive, especially if the player is looking for college opportunities.
We had our disillusionment come in our 2nd to 3rd year. After first year on the B team, got moved to the A team, did ok but not great, was promised a spot verbally for the next year, then got cut via online roster posting (no email, no phone call, no conversation) day after tryouts where she was the only keeper in attendance. Utterly devastated. Went through the process of shopping other clubs and had very similar experiences as you did. She found an awesome team one age group up that wanted her, practiced for a few weeks with them, they loved her. She did a showcase with them had one great game. Coaches were over the moon about her. Second game, gave up a real howler. Coaches were like, "It's ok. It happens." Third game, it happened again. "Thanks for coming out, here's her player card."
Like you, I worried that all this crap was going to ruin soccer for her. I don't know why, but it didn't. She kept her desire through it all and even through puberty and the sudden awareness of the opposite sex. I don't think I can take any credit for that. She just kept persevering. Maybe your son will, maybe he won't, and either outcome is totally fine as long as he's doing it on his own determinism.
I can't really offer you much new advice that you either don't already know or haven't already been told here. I will say this however, about keepers: The experience of getting cut because of poor performance did get in my daughter's head. As a youngster, she played with abandon and aggression and that almighty superpower of great goalkeepers: confidence. That was because she was usually one of the top 2-3 players on the team. She had a coach that didn't punish her for mistakes, and she was the only keeper on the team (we also wanted her to play in the field some, but that never really happened...a topic we can discuss in DM if you want) so she always had the comfort of knowing her starting GK spot was secure. As a result, she played great. In the situations where it was known that her spot was questionable or that she had to "earn" her place, she played tighter. Once she had the hammer put down on her, she started tightening up in every new situation or in every big game, fearing that a gaffe or a soft goal would get her cut. It has taken a long, long time to build that confidence back. Whatever you do, you need a coach that is going to let your son screw up, let him lay an egg, get megged on a break-away, have a slow roller go right through his mitts. Every keeper needs a coach who will let that happen, work on constant improvement, and build their confidence up. I know you want him to play in the field and split time, but honestly, my daughter's best experiences have come when the coach is committed to her as his/her #1 keeper and not constantly shopping around for the next best thing. I highly recommend B teams and lower Silver or flight 2/3 teams for goalkeepers. If your team regularly gives up a couple goals, but the keeper saves 7-10 shots a game, everyone on the team is highly appreciative and the GK feels like a hero. On the flip side, if he plays for a great team and only faces a couple shots a game, but gives up one out of 2, the looks of resentment and pressure to be perfect can really break a kid.
