Just because a student doesn't score above 145 on a cognitive assessment doesn't necessarily mean they will be able to be accommodated in a regular GT classroom. Some will, and some won't. I would probably have put the range of can-manage-okay as more like 120-135, with the upper end depending a lot on their personal strength areas and temperament. I would agree, though, that a GT classroom, even one without accelerated curriculum, may bring school within the just-tolerable range for some of those 130-140 range learners. That's a far cry from being an actively good learning environment, though. And it won't be enough for some even to tolerate going to school.
On your DD, low rapid naming is definitely a red flag for word-level reading disabilities. Her rapid naming and reading fluency are not normatively low, but they are certainly a whole lot lower than her verbal cognition appears to be. How that plays into qualifying for special education depends on your state and district regs. How is her actual word-level reading, especially of nonsense words (including tests with names like word attack or pseudoword decoding)?
And since you suspect some kind of reading difference in your DS1 as well...you note that he reads well above his grade level; what are the signs of reading challenge that you see? What does he do well/poorly with when reading? Happy at school is excellent, and more important than most other educational indicators, in my book. But if reading or writing are at all aversive to him, despite his high levels, it may affect his educational and career choices.
On your 3rd: I think we discussed some of the options for addressing social needs in homeschooling settings. If he is in intense distress right now in school, and you don't appear to have options for changing anything for the remaining month of school, it may be worthwhile to consider the homeschooling option. Clearly, he won't miss any necessary instruction (he wouldn't even if he weren't above grade level academically; it's the last month of elementary school--the traditional domain of field trips, field day, and popcorn/pizza parties), and it appears to be causing undue psychic pain to continue attending school.
