Now to answer your diagnostic questions.
School counselor suggested a potential motor-planning issue bc DS was irritating his teacher by being slow and clumsy with his (big) binder. This is not the same as a fine-motor issue, correct? School OT administered VIM (I think?) and he was above average.
You are correct in identifying that motor planning doesn't have to be fine motor and vice versa. DS has a motor planning disability, and his fine motor testing showed incredible control. His teacher asked 4 times if the results were for the right kid. His handwriting it terrible despite this. The planning problems are at a much more executive level than the fine motor planning tests evaluate. As in, it could be his apraxia/dyspraxia, it could be ADHD (and it could be lack of handwriting education).
2) Constipation/encopresis issues, severely delayed full toilet training, nighttime enuresis (improved but not resolved). Not in DSM. ASD symptom?
And also highly correlated with ADHD.
3) Pragmatic speech issues mostly related to inability to monitor himself appropriately and anticipate others' reactions. EFD or ASD? This one seems to be the most obvious ASD thing...but could be discrete disorder?
Some of the boundaries between parts of ASD disorders have been separated out as smaller sub disorders. My DS fits a profile (though I'm still not sure it's accurate) of having social pragmatic communication disorder with no other boxes ticked for ASD. Though, alas, I view his responses on the testing that diagnosed this to have been a consequence of other issues. The treatment for it, however, should be broadly similar, so this label is getting him appropriate (ish) services.
6) Huge spread between GAI and PSI on the only FSIQ he has ever taken, age 7. However, his IQ has been all over the place, even just the GAI. High at age 5, borderline gifted at 7 (but he was very stressed), high again last year when re-tested for this program (but not as high as it was at 5, by a long shot).
It will be instructive to see how these scores change with time. Make sure to disclose these scores to the neuropsych.
I am starting to think that he is much more unusual than I realized,
Um, yeah, DS evidently "won" the award this year of having "the most complicated profile in the school." Yeehaw.
