Shortcuts for palette symbols
There was a discussion on another thread https://musescore.org/en/node/59456 about not being able to add sforzato from the keyboard. You can actually assign a shortcut for toggling this, but there are a lot of palette symbols that cannot have shortcuts assigned to them.
I would suggest allowing all standard basic and advanced palette symbols to allow for hot keys to be assigned to them. I basically used 10-15 symbols on nearly every score I use, and not needing to scroll through my palettes to find the right symbol would be a great improvement.
One way to implement this would be to have the use be able to right click the symbol in the master palette and under properties assign the hot key to toggle the symbol. Right now every palette symbol I use can be assigned by clicking a note and double clicking the symbol, why not let the shortcut add a symbol or remove the symbol.
I would suggest that you make an internal shortcut map (which probably already exists) and if an existing shortcut is entered (such as ctrl-b) a confirmation message would appear that says "ctrl-b is currently assigned to 'Append one measure', replace this shortcut?" with yes (replace the shortcut), no (which would return the user to the preferences window) and cancel (which would close the preferences window) buttons. The preferences window would of course show the currently assigned shortcut to any applicable palette symbol, so the user would know if he were replacing an existing shortcut.
This would prevent the ambiguous F2 in 2.0.3 being possible and add flexibility to the user.