Hi there, that was certainly quite a read.

Firstly, the best person to tell if you are on the spectrum is a professional, none of us can really say that you are or are not based on symptoms alone. The reason I say that is because the whole thing about the 'spectrum' is that it's not a fixed list of symptoms which mean you for sure are on it. A lot of people on the spectrum have varying symptoms and at varying degrees of severity.

I can relate to some of what you mentioned from your childhood, however as I said that isn't a sure fire guarantee that you're on the spectrum. It could well have been a mix of your ADHD and possibly an anxiety disorder of some form.

Problems with early motor skill development are more so linked with Autism than with AS, generally those with AS don't have the same early developmental problems which is why it can be harder to spot it early on.

You are correct that any ASD is a life long condition, though some people are able to learn to 'cope' with it better than others. This may simply be down to the varying degrees of severity, or perhaps some people are just better at adapting than others.
I know that for myself at the age of 28 I still can't look people in the eye or hold a conversation unless the other person continually guides it along. I can't deal with change to my routines without having a meltdown (a lot of the time, I can deal with the change better after the meltdown but never before, it's kind of like it acts as a 'reset').

I have seen people with AS who are able to have full fledged conversations and even hold the attention of an entire room full of people, but yes they usually have to do a lot of stimming before or after that to deal with the sensory overload and the other issues that arise from social interaction.

Sorry that I can't be more helpful.