It would be great if I could select to points, change the width and height, and the results changed the same way that they would if I had nudge the points into place.
You mean a numerical nudge as opposed to a moused nudge?
You can nudge with the keyboard too: hold down Ctrl+Opt while you move the points with the arrow keys. Add Shift for increments of 10. That’s more precise than with a mouse.
I know about the shortcuts. But it would be really fast to just type +80 next to the width between two points, hit opt+return, and get an instant change.