Welcome, Renee. If you need to make any changes, ask a moderator to help and they can wave their electronic magic wand and fix it. A pity we can't fix our kids' problems the same way!
I have a cousin with a mild form of OI. His lungs kept collapsing, until finally they had been fused to his rib cage and there could be no more problems. He's doing well, he's a grandfather now.
I really get you about the physical stuff being easier. A neighbour of ours, a little boy, acquired CP after a near-drowning. He and difficult child 3 were classmates at pre-school, and they both had support services. But it was interesting - I spent time with this boy, and he was easier to babysit than difficult child 3! I could talk to the CP neighbour, even though he was non-verbal. But he understood, he could follow directions, he could sit quietly and contribute (one way or another). He learned to communicate via computer, and I believe has been doing well in school.
And you've got a double-barrel set of problems! Part of the temper outbursts could be frustration, he may still be adapting to his disabilities. It does take time. Before they begin to adapt, it is (I think) the worst time.
Marg