thank you very much for playing and letting me know everything that isn't working. it's impossible for me to find on my own.
the first problem i'm not really sure what you mean, but generally people try to dash after they exit the water-sphere. try dashing before you leave the water sphere. see if it solves it. (yes i know i need to teach my mechanics better, i haven't figured that part out yet)
if you die the level resets and you lose all unsaved progress. checkpoints are only for when you still have health (like falling off platforms).
that last one is something i thought i had fixed. those things don't actually destroy when you dash them; the get placed very high up. so if you stand on top of em they'll take ya for a ride.