You can also move the node of a vector by selecting the black node (it turns red) and then using the arrow keys. Or use the numerical pad arrow keys with the Num Lock turned off. How much it moves with each stroke depends on how far you are zoomed in.
That is pretty nifty!!!
I have been a user of this software since March 2016 and was totally unaware of this feature. The more you Zoom in the less the node moves/nudges.
Note: You really don't even need a node selected. You can actually move a feature (circle, box, etc...) using the numerical keyboard (4 left, 6 right, 8 up, & 2 down) or if your keyboard has arrow keys you can use those!!!
AWESOME Tip!! Thanks Brian!!!