I had a mosh connection open before I got on my last United flight and was able to use it the whole time. Seemed to me the free messaging/inflight entertainment tier doesn't block arbitrary UDP packets at all.

Even the terminal build supports the mouse. `set mouse=a`

In general yes, but there are still some cases where mouse is better than the equivalent keys. Mainly resizing splits (guess how many lines you want and then C-w <size>|, vs just dragging the divider).

:set ttymouse=sgr also makes it a lot smoother.

This was a revelation for me as well. I also didn't realize that if you haven't configured vi keybindings, the default is Emacs (in bash or anything using readline). Even though Vim's my main editor, I found modal editing a bit too heavyweight on the commandline, so I prefer the default Emacs (most useful by far: C-b to go back one word and C-k to delete everything right of cursor).