Just wanted to write up some UI/useability ideas I had. Many of these are inspired by how unreal's blueprint editor works:
1. Right click anywhere to bring up a list of all nodes with a text input at the top that filters the list as you type. Makes adding the node you want very quick
2. Drag an input/output into empty space to bring up a list of nodes that could be connected to that input/output, again with a progressive filter input.
3. The ability to rename nodes is cool, but the fact that you then lose visibility of what type of node it actually is worries me - maybe there should be a separate 'label' field for the user to enter info rather than replacing the name of the node type. Or at least put the node type in the tooltip.
Anyway, with or without these it's a great tool, nice work!