As far as how Jeffersonian policies confliected with the vision of Handsome Lake, I don’t think there was a conflict. Both were pro-agrarian and Handsome Lake’s sympathy to Christianity, despite his calls for an Indian cultural revival would put him less at odds with Thomas Jefferson than would have been expected given his initial resistance to Christianity. Both Handsome Lake and Thomas Jefferson seem to have been productive personalities and I imagine that they would have had much in common since they were both pragmatic in the way that they handled the situations placed upon them.
The primary cause of the War of 1812 was a desire for expansion on the part of war hawks whose nationalism manifested itself as a strong desire to increase the amount of territory under American suzerainty. The frontiersmen of the North wanted to see Canada become part of the US while those in the