Deborah. I know you want answers to all you linked to on a personal level, but you won't find it in links, or words. The seminars really are something you would need to experience for yourself. If you're not interested in going, but want answers on this forum, doubt it will be.
Seminars: It's a view shared by a few. No one person gets the same thing out of the same seminar. It's different for each participant.
The coaches are hired by the parents during the transition phase, coming home phase. It's not mandatory, but a choice. How wonderful to have that support available. Don't other programs just say "bye" and don't offer much in the way of support once the child has graduated? That would be another thing to look at.