I have an idea that I believe will be useful. I'm thinking that when you use the line tool, it should tell you how many pixels long the line is before you draw it. Also, with this idea there should be a "ruler" that is on the element menu, and when you draw with it, it doesn't do anything, but it is used only to measure things you have already made.
I'm sure I explained it badly, but I think it would be nice to not have to count each separate pixel.