Wolfson -
Are you planning to move to public school if you send your son for 1st grade in the fall? (I can't call the move to 1st a 'skip' because he's just following along naturally what he did last year in K, I guess I'd call keeping him in K an 'age-based retention' and sending him to 1st 'normal for him.'
Either way, I think that the drawbacks of being younger are usually far less than the drawbacks of being in a classroom that is a poor fit. It's true that it's easier to be flexible in kindy than other grades, but those inflexible grades will follow, and why not stay with one's friends when possible.
I think your mind will be set at ease if you do some reading -
IRPA - A Nation Deceived
www.nationdeceived.org/ Peace,
Grinity
