A very basic feature missing right now is to temporarily switch to Selection Tool by holding down ⌘ and to Node Tool by holding ⌥. This should work with any other tool active and like that would allow much seamless drawing experience, since often after having created a shape with any drawing tool, we want to move or modify it using either Selection or Node tools.
Right now we always have to hard switch to these tools and then back again to the chosen drawing tool, which means looking away from the screen and down at the keyboard to hunt down the right keys. This is especially painful right now with the Pen tool, which often requires repositioning the nodes as we draw them, but since we also cannot move the last Node by holding down Space (another basic feature that should be there!), we have to do this constant dance between P and A keys, which are located at the far ends of the International QWERTY keyboard. ⌘ and ⌥ however are right next to each other, so by placing your thumb and index finger on them you’d never have to take your eyes away from the artwork as you create it.