Ok thanks for the info. For the cursor you could try to make it so that it blinks between different colors when you are selecting the second line point so it's easier to distinguish. Something I wonder though is how you will work out the issue about stuff being erased when you move the cursor over it? Recalling the picture would fix it but that's slow.
I can make it a circle when it's selecting the second point, and I'll work on it.
As for the stuff being erased, you can turn on no-erasing-cursor mode (freeform drawing, for now) and go through the line like that. I'll see if there's anything I can do to minimize cursor erasing.
Speaking of that, I have done a few things:
*Saving and loading
*Freeform drawing
*Other miscellaneous things
I will upload a screenshot when I have time.
Edit: Added the different cursor. It now blinks between circle and solid, but I don't slow down a lot so you can see it.