Remove (or improve) "P" and "Y"
It's hard to describe how many problems these 2 keys cause. The fact that any ship connected via a connector (or landing gear at the time of writing) can disconnect (bad) or power down (extremely bad) every connected grid. It is to the point where basically every person who makes a tutorial says many many times to NEVER PRESS P (or Y).
So honestly either remove the function (which sucks, but at least we won't have people breaking other people's stuff by accident because they pressed one of these 2 evil key binds). Or if possible make it so the function only affects the "mechanical" grid so sub-grids attached by pistons/rotors/merge blocks will receive the effects of P and Y while grids connected through a connector will remain unaffected.