1. A culture as xenophobic as feudal Japan's would certainly just heap assistance on an outsider with a weapon they'd never seen before.
2. Although they may look like gargantuan sticks of cotton candy, those are in fact trees in the background.
3. Simply put, the human body will not generate a fire that size unless generous - and I do mean generous - amounts of lighter fluid, or equivalent, are applied. Are these people just that impractical, or - oh. Whoops. I forgot who was drawing this for a moment. Sorry.