Why are US airlines so bad?

In general, US carriers seem much more cheap and stingy than their European and Asian counterparts with little difference in fares. First of all, complentary food is nonexistent in coach in the US (not even on 6 hour cross country flights) while it's commonplace in other countries (example: China). Second, US carriers' planes are always in terrible shape. The plastic panels are yellowed, and badly scratched and scuffed up, seats are heavily worn and battered, and all the furnishings very dated and look like they havn't been updated in 20 years. International cabins are OK but flying domestic on, say, United, is like flying a budget carrier overseas but without the lower fare.

How does an airline overbook flights?

When you book a flight through the airline's website or over the phone, you can select which seat you want and seats that have been chosen are not available. Wouldn't that prevent more than the aircraft's capacity from being ticketed on to the flight?

I have a flight in Atlanta but I'm confused

I've alwsys flown direct but this time I have a connection from Atlanta to Boston then to London. Since I will be going to Boston first which is domestic I'm not sure if I go to the Atlanta domestic airport or the international airport. I board at Terminal N Gate D2. My flight is tomorrow and if I go to one and it's wrong the drive takes 30 minutes I don't want to miss my flight.

Added (1). The booking doesn't say which one and I've googled but I can't find the right answer

Haneda airport terminal to Arakawa?

I'm going to Japan and my flight arrives around 11:30pm in Haneda airport is there any bus or subway route I could take to Arakawa-ku? I want to figure out before having to reserve for taxi bc it is expensive.

Added (1). I'm also wondering how long is immigration at Haneda?