4a.) Should I upgrade to economy plus.
Yes, by all means, if biz is not an option. I don't know how tall or wide you are, but IME coach in UA 747-400 international flight........I'm traumatized by the memory.
I am a little worried about making it through the flight. I have had bad experiences where the entire plane used the bathroom like 2 times a piece when flying from PHX to FLL. or Screaming kids. (I know its hard for them but what to do - Do the bose noise cancelling really work that well? lol)
The BOSE are really good.
Like someone said, take your own entertainment,see if you can round up a few extra cushions for a bit more padding in the cracks and corners in the seat and you're all good. (kinda)
Safe Travels !