There are no right or wrong answers. Even if your DS had scored in the range you expected, it would not guarantee that the school using the scores as a minimum requirement would have been the best fit.
Yes. Some gifted programs and schools are positively toxic. You want to look for flexibility and relaxed-ness, IMO. I don't know what the buzzwords to look for are, but I do think a high pressure, high output school would be unwilling to take the time to get to know him and see past the perfectionism and low working memory.
