Graham - once again, you post what you'd like things to be, not as they are or ever were.
1. In Japan, firearms were definitely considered martial arts. By the end of the Edo period, there were several hundred 古式砲術 (Koshiki Hojutsu) schools. They included cannons. The ryu were mostly abandoned when they found that the Western systems of gunnery were better. LINK
Your assertions are ahistorical. It is simply not true - pure fantasy - although widely disseminated fantasy that martial arts were done in temples and then "borrowed" by warriors. The militant Buddhist temples of Japan were havens of thugs, who slaughtered celebrants of other shrines and sohei of other temples. The military arts of the Shaolin temple were, in fact, consolidated to fight Wakou (Japanese coastal raiders who were the Eastern equivalent of Vikings).
If you ask any practitioner of an authentic classical ryu what the purpose of using the sword is, he or she would assert that it was for learning how to kill. Group solidarity and moral training were contributory to that end, in large part so one could effectively do it in cooperation with others.
There is no doubt that modern martial arts are often focused primarily around self-development. Tae Kwon Do classes for learning disabled kids. Aikido for the blind, the halt, the lame, the hale and the hearty.
And you know what? I think that's more praiseworthy than learning how to kill. I think its good that good people have a place to practice good things.
Except to be safe in many parts of the world, one has to know about killing too. Which is why, I think, Nidai Doshu ended his story with his father running out of the house with a bokken in his hand. The only thing he didn't say - and I always loved Doshu for his very dry and quiet humor, is if, his father, before he fell in the mud in his Sunday best, intended to thrash the foreign bullies, or to thrash his own son for being such a wimp.