Hello there,
Thank you for your feedback.
All things you have mentioned above are done to make the game a bit challenging.
1) If you are getting damage even after simple jump try setting monitor refresh rate to 60Hz (if you haven't already). One of the user figured out this solution for that issue. I will add an option to turn it off, so that anyone want the game challenging can keep it on.
2) You jump on sides you can decrease your speed by pressing opposite direction button. For jumping on same spot I will add some code to move left or right.
3) I gonna keep this one as it is. I find it useful when you wanna bunny hop your way anywhere. I know this is not something anyone would expect on the first play. That's why I have mentioned it in some part of tutorial in level 1(if level 1 is not completed).