The relevant piece of IDEA you're looking for is the following:
"(b) Children aged three through nine experiencing developmental delays. Child with a disability for children aged three through nine (or any subset of that age range, including ages three through five), may, subject to the conditions described in Sec. 300.111(b), include a child--
(1) Who is experiencing developmental delays, as defined by the State and as measured by appropriate diagnostic instruments and procedures, in one or more of the following areas: physical development, cognitive development, communication development, social or emotional development, or adaptive development; and
(2) Who, by reason thereof, needs special education and related services."
In other words any developmental delays including a physical one like a fine motor delay that can be measured (by an OT/PT) qualifies by itself.
However, the other part to think of is what services do you really want? A fine motor delay at least around here usually means a pull-out session with school OT. The thing is that the quality/frequency of the therapy and the lost class time are both trade-offs. You may find that a private OT works better for you.
Trouble staying in your seat or not asking for help are much harder to quantify although they would fall under social-emotional. The problem is that some amount of that is developmentally still appropriate and so qualifying is more subjective and probably easier to do if its reached the point where he is disrupting the class. But even assuming that you do
reach a consensus with the district on that score, do you want some kind of social/emotional intelligence pullout for these behaviors? Because an IEP most likely will not be a lever to get more challenging work to relieve boredom that leads to leaving the seat etc.
Good luck
