Motor Dyspraxia & Sensory Integration Dysfunction

My 10 year old son has motor dyspraxia, hypotonia and sensory integration issues but is very bright, learned to read at 2 1/2 and read at about a 5th grade level at age 5 and was tested by an educational psychologist at age seven and was at that time working several grade levels ahead  of agemates in all subjects.   However, handwriting difficulties and fatigue issues would make it difficult for him to spend all day in a public school, so we have to homeschool.
  
There is no family history of sensory or motor disorders and we would like to know if it is possible that a difficult birth might have caused his problems.  He was full term and my labor was induced with pitocin, my husband says it looked like his heartbeat  had stopped when they told us we had to get the baby out NOW and they had trouble getting him out quickly and had to use forceps.  The cord was wrapped around his neck.  But he did start breathing and we thought everything was okay until he we noticed he was floppier than other babies and his leg muscles seemed weak.  He didn't crawl, couldn't pull himself up until he was 13 months old and didn't walk until 18 1/2 months old.  A test at 12 months showed he was 6 months delayed in gross motor but he was 6 months advanced in receptive/expressive and was saying some words.  He has always been very verbal and people have told us for a long time that he talks more like an adult.  His adult half-brother is highly gifted and was similar in some ways as a child but did not have dyspraxia or hypotonia.

My son had a total of 6 sessions with an OT.  She told us she was doing sensory integration therapy with him and it seemed to help a little, but our insurance stopped paying for it.  He has never had anything else for hypotonia or motor dyspraxia.  The OT and the developmental pediatrician said something about therapy being able to help him form new neural connections.  Is this really possible?  If it is, why is it so hard to get insurance to pay for sensory integration therapy?  

My son is crossing over to Boy Scouts soon and they are talking about doing 10 and 20 mile hikes.  My son's endurance never seemed to increase that much even when he went to sensory integration therapy.   Is there some kind of therapy for hypotonia and dyspraxia that would help him with the endurance issues enough that he could keep up with other kids physically?   Is it okay to push a child with hypotonia and dyspraxia to keep going when he says he is too tired to go on?