[Burgers]

Lousy experience.
FID's (Flight Info Display) is maintained by the airport not the airline.
Goofy layout of the airport, lack of electric carts etc is an airport issue, extraneous to your complaint with American.
BBB has zero authority, its a business and a bit of a scam in that people actually think they have some sort of authority when they don't.
Your compensation number is unreasonable. You want your ticket price refunded plus cash compensation, zero chance of that happening. Miles tossed your way with a polite succinct note, otherwise you'll be on ignore. You've already griped publicly once you do that you can expect very little in compensation. With the advent of social media, etc people gripe way too quickly not realizing they've pretty much earned a big fat no in the future by doing so.