First of all, there should probably be a way to move a node whilst you're still editing it: de-selecting them just to drag them is annoying, and it's hard to not accidentally add a second.
Also, when dragging a node, it would be a lot nicer if the directions of movement were preserved. For instance, if I set a 200m/s prograde burn, then drag it 90 degrees around the planet, right now I'd end up with a radial out burn, and have to delete it and start again.
My third thing is that it would be great if we could drag the editing handles towards the node as well, which would have the opposite effect of moving them away. This direction could be made less sensitive, so that more precise burns can be made.