In all the talk of graphical downgrades no one seems much preoccupied with 'why?'. Why build something and then proceed to tear it down, piece by piece, in the hope that ever more diminished expectations about the final product won't be severe enough to...
If you're not getting far enough with your jump, try sprinting before hand.
You can jump on water if you tap the screen quick enough after you fall in.
Sometimes, ignoring a bad guy is a better idea than trying to kill it.