You probably have already learned this and the two guys offering to help you are certainly aware: it's really easy to add bugs to your code and wiring.
Is there any possibility of damaging your crane if, for example, the object being lifted is pulled off the ground before the counterweight has moved into place?
I suggest that you need to think carefully about how you can test thoroughly and safely. Using an epically boring stepping rate might help to start with. I'd add a manual e-stop button too.