If your run is still awaiting verification (which it is not currently, I don't know what you're talking about), you will have a run pending for verification. It is neither accepted or denied, you should definitely wait.
No, Unity removed the feature. If you would like to remap your keys, I would recommend an external program. Just make sure to not rebind non-mouse keys to your mouse!
Sure, it's perfectly reasonable for you to run this, give it a shot. A lot won't, I only imagine 3-ish, not very much.
Yeah there isn't really progression to this game, or missions in order to call it 100%. Like jannik said, if no one will run it, it wont be a category. Remember, you can always run categories yourself, it doesn't have to be on src, you could even create a thread dedicated to 100% and post your times there.
You don't spam slide before the jump. If you're talking about the SJS, you do not spam slide, you slide and while sliding jump and uncrouch, then crouch again to do a crouch jump. Level 8 is a good level to practice SJS, as well as level 3 and level 0, as for GDJ, level 1, level 2, level 3, level 5, level 9, and level 10.
By sliding I assume you mean spamming crouch in order to get upwards of 54m/s when jumping. You can do that by spamming your control button by moving your hand off of you mouse onto your control button, and then it's pretty easy. If you mean sliding then jumping then crouching, it's not too hard. All you have to do is slide and crouch jump, as that your crouch jump begins with more speed.
If that is what is really happening, then no, I don't believe that should be considered a glitch. Now if there's some kind of weird physics stuff happening where you are crouching then jump, then un-crouch making you stand on the floor again, then crouch jumping, I would believe that that could be argued would be a glitch.
I'm not sure, maybe, depends on how it works. Not sure.
Well sometime people do this on accident, so you wouldn't want to be too strict on the rules. Imagine losing a run because you got an 4 extra speed.
People do GDJ on accident, it's a bummer, yes, but just because a glitch happens on accident, doesn't mean it should be allowed or be lenient.
When you slide and crouch jump, to go from 31 ms to 46, rather than 24 to 42, is that a glitch? Should it be?
No, all enemies and all powerups should not be 100%. This game does not have a clear line of progression apart from the levels. There is no reference to "completing the game all the way" and does not show any slight reference to progression outside of the levels. Easter eggs would be included, certain routes could be included. All of these constitute to an 100% run, and there is clearly no line to show "Wow! You just completed the game 100%" to allow for such. It would be either just called all enemies, or we just might not have it at all.