Son, on the spectrum, dangerous behavior with siblings.

Good morning/afternoon/evening all. 

This is my first post here, and I come because I am at my wits end and I am unsure what to do. Really, I just want to get things off my chest, ask a couple of questions. 

Firstly. our son is on the spectrum, and he has recently been statemented. Alas, my wife knows much more about this and takes a direct involvement with communicating with his school and teachers so exact details of how all this works. 

It is also of note, that I am 35 years old, and I believe I have some form of Autism that was never diagnosed ( something I am seeking to have done) I believe I have Aspergers. Based on that, I question my capability to handle my son and do whats best. 

Anyway. This morning, I caught him messing around with a plastic bag he had found somehow, and placing it over the head of his younger brother. His younger brother obviously did not appreciate this, so he cried out. My son shushed him up, and when he heard me coming, he threw the bag to the ground. 

My son knew what he was doing was wrong, and dangerous, and tried to hide it. He has been separated at this point. 

I grow concerned because this is not the first time something like this has happened. My first son is 6 years older then his nearest sibling, 11 years old. 

How best would you handle incidents like this? Is this sort of behavior to be expected? 

Generally speaking, he is a very loving brother and family member, but he has these incidents randomly and they can be outright dangerous at times. So, I am concerned. 

On a separate note. MY son and I have always had a strained relationship. I have two other children, who most certainly are not on the spectrum, and I have a very loving relationship with both. However my son won't allow me to touch him. I tried to hug him in public the other day and he was having none of it. He doesn't show love, and I genuinely believes I don't love him like his siblings, although this is definitely untrue. I just don't know what to do for the best. If we don things together he gets bored/destructive and ruins the session. He is extremely immature for his age. Also, I never once, ever, heard him sing. Not a single note. I find that odd too. 

I can best describe our relationship as two magnets repelling each other. In that they belong together, but repel at point of contact. 

I am very concerned. Any help at all would be wonderful. Even if it to tell me it'll get better as he matures. 

Thank you in advance.