At the time of the Presidential vote. The Embassy posts a guard outside the Embassy. He/she will accept your absentee ballot and it will be in a diplomatic pouch the next day. For other elections simply drop off the ballot at the Embassy.
Sears did not die because of Amazon. Try arbitrage, for starters.
However,Trump views Jeff Besos as his personal enemy and will do anything to harm him.
And you are correct, Trump knows less that nothing about trade and or economics.