Drag and drop icons existing on toolbar to easily re-arrange them
I think it would be useful to have the ability to easily re-arrange the buttons of the toolbar. E.g. In menu edit mode LMB hold down on button will move/drag the button into a new position on the toolbar where LMB is released.
Also, if the button is moved near to left or right edge of the toolbar it could be moved to the next or previous button set (or context menu can pop up with items like Ctrl-1, Ctrl-2 and so on and dragging the icon over a menu item the toolbar will jump to that button set. This way one can easily move a button from let's say set 1 to set 4).
Dragging button outside of the toolbar and releasing the mouse button could be used to quickly remove button from toolbar.
Ability to handle more buttons at once can also be added, but perhaps this is less important, because if above actions can be executed quickly the efficiency is almost the same.
Happy SE-ing both to the community and to the devs, too!