Instant typing focus
Something that would really speed up workflow is immediate typing focus when selecting (clicking) nodes that have a single type-in control (especially function nodes, like constant values).
In addition to selecting, it should also happen immediately after creating these nodes. But I think newly created nodes are selected immediately anyway.
The only issue I can see this causing is interference with hot-keys while such a node is selected. But as long as hotkeys are typical (eg, ctrl + key), it shouldn't be a problem. No different than trying to use a hotkey immediately after typing something into a typical control. The user can just press enter to get back to the normal state in either situation..