You have to switch to parallel view in order to draw the lines correctly or they will be arranged all over the place. It took a while for me to find that out. I use SU only. Sometimes it is a bit stubborn but up to now I have found a solution to every problem. Don't give up! Once you have mastered it, it will be a very useful tool serving you well in future projects.
I tried working with dwg files but that process was a bit complicated. I had to redraw every line to make it work so I ended up importing jpgs of the images and redrawing the lines "the traditional way".