I think it would be a silly idea to try to rename American football now. It is too ingrained and defined, and while there are points of confusion at times, it is hardly a big deal.
However, for pure descriptive purposes, football makes a lot more sense as a name for soccer, since you do primarily use your feet in that game, and football largely doesn't. Of course, MANY games are not descriptive (I believe you don't even USE a pickle in pickleball) but never mind.
So, if you were somehow unburdened by reality or tradition and were seeking to give a descriptive name to football, what would you name it?
Passball? (It isn't just passing)
Sphereoidball?
Padball or Armorball? I kinda like Armorball, but that might be because I am a massive nerd.
Crashball?
Tackleball?
Hikeball?