Hmm, much agreed

Not Recommended.
Cause i find this a great addition to the game, only cause sometimes when im launching scouts of my Monty i load 2 on accident then i have to launch and return which takes 2 much time. so i can press ~` Key and i can load up 1 scout.

Recc, I had a habit of spmming the ` button when the fueling is nearly complete so I dont waste any time in between fueling and launching. make the cancel button - or = or something.

You mean also that you can cancel your load of aircrafts after they are ready so you can launch them or?

I agree with changing the cancel button to some other hotkey. I agree with being able to cancel when your planes are fully loaded. For example you finish loading your bombers and a enemy CV comes with a fresh wave of fighters and camps you. You won't be able to launch the bombers unless you want them to go to their deaths immediately and you can't load fighters to kill the enemy fighters.

I don't agree with deleting the 10% cancel time. There needs to be a penalty. 10% is a good amount. 

Yes, allow hotkey change in F10.