You'd need to define your criteria by which you define "better". Most military doctrines dictate that riflemen fire in semi-automatic, and are supported by automatic weapons. Which is "better" depends on purpose, typically.
No specific term of reference. There are semi auto pistols that fire rifle cartridges, and are much more powerful than standard pistols.
Revolvers are pistols. Whether a revolver is better than a semi-automatic has been debated for almost 100 years. It depends on what you like, intended use, etc..
A TRUE Assault Rifle is legally a machine gun. They are used by military and by specialized security forces, and shot by a very few collectors that can afford a several thousand dollar rifle. What people are CALLING an Assault Rifle, such as the AR-15, is nothing more than a semi automatic rifle. They are used for hunting, target shooting, and self defense.
Yes, manual is better than automatic gears.
BAR stands for Browning Automatic Rifle, not browning association rifle.
No, not in the least. And maintenance on those transmissions is much more than it is on the manual transmissions.
if it fires more than one round (or BB ect.) it is not. By definition semi-automatic means it will fire with each pull of the trigger.
if it has a semi automatic/automatic switch, than yes it IS illegal to own or sell outside the Military
no
The Steyr AUG is a automatic assult rifle with no known civilian trigger group model that I know of. If there isn't a semi-auto trigger group that is non interchangeable with the full auto rifle than it falls under 12(6) prohib which is illegal to posses
It's a semi-automatic cartridge that is a little smaller than a .380 but bigger than a .25.
In MOST states it is 18 to own any shoulder-fired weapon. In order to own what the military considers an assault rifle, you also have to have a Class 3 Federal Firearms Lisence, but some states and cities definition of an 'assault rifle' includes anything that looks dangerous and NO ONE is allowed to own one there.