Question #1They wanted someone to provide a reason as to why owning a semi - automatic assault rifle was necessary and in what scenario it could be used efficiently for good (and other means of protection would not work, glock, etc...)
The definitions of an 'assault rifle' vary from state to state. In California (where I live) we have a list of guns banned by name (Roberti-Roos list) and by feature (sb23). SB23 basically says that if a rifle has a detachable magazine and any of the following, it is an assault rifle:
1) pistol grip
2) folding/telescoping stock
3) flash suppressor
4) bayonnette lug
5) thumbhole stock
There may be others, but those are the big ones. A lot of older battle rifles were very popular with the hunting crowd.
The M1A (A civilian version of the M14), a .308 with a detachable magazine and a flash suppressor became banned over night. This is a long time favorite of collectors, competition shooters, and hunters.
In terms of home protection, an AR15 is not an ideal weapon. Firing one inside the home is not recommended due to concerns the bullet could travel through walls and into unintended things like children. Which is strange because you see SWAT and various other law enforcement agencies using them.
If you go on hikes or live in a rural mountain area, an AR15 is a great companion for safety. The reason we use it in the armed service is the same reason it would be effective in this scenario. It is light, minimal recoil, and accurate. Quick follow up shots and tight groupings allow you to subdue or ward off most threats you'd find (except a bear. wouldn't want to test that would want something bigger).
Question #2 - Should folks with mental disabilities, aspergers, autism, mental illness be taught to shoot gun for any reason?
This is a tough one. There are varying levels of mental disabilities. Just because someone has a difficulty reading for example shouldn't mean that they can't defend themselves.
As far as aspbergers/autism goes, there are a ton (probably millions) of high functioning autistic that just seem to be 'odd'. They can be very successful (they seem to do well in engineering roles) at work and life. It would be a travesty to disallow these kind of people from enjoying the challenge of competition shooting or self defense.
This honestly should be on a case by case basis.
Also, I won't pick this thread apart with how wrong a lot of the answers are, just because you said no digressing!