Hot-Key for left (and right click). Maybe a key-cursor...
This feature request might sound a little odd at the first glance.
I would love to have a keyboard hotkey for left (and why not right) click. Why? When I try to work very fast, I noticed, that clicking with the mouse / touchpad while controlling the mouse-cursor I get much more slow, then when I would use the mouse / touchpad to just control the cursor and do the drawing / clicking with the other hand. Think it like e-sports.. So having a hotkey for left mouse press could increase working speed.
The other idea was to use the cursor-keys to control some sort of cursor on the screen. Just like on the C64. It would be much more easier to draw straight lines, diagonal lines and small details at a higher pace.