How to create hotkeys for specific modes that override the default ones? "G" in object mode = move, while in Sculpting mode = Grab brush, 

I want to edit the shortcuts for many brushes, but i'm having an issue, for example i want to remove the "S" key from the Smooth brush and assign it to the "Scrape" brush, but its not working, "S" is always smooth, even when i right click and remove shortcuts from it and add "S" to scrape, also, is there a place to see all shortcuts for every mode so that i don't accidentally override some important ones ?

thanks!
Maybe you know it already but if you go to edit menu>preference>keymap you'll have the choice of the shortcuts for every windows and mode. Also the trick I use is to right-click and assign shortcut when I'm navigating the menu bars.
Let me know if it works for you! 
Cheers
Fred