first, my name is pronounced "proosha".
As you said, its old model, no reason to bitch about it in 2013 you are three years too late ;-)
It is still built as there are thousands of ppl who can help you with it.
Hanging Z axis was made because it transfers less wobble to the print, now with tube couplings, its not needed. Your coupling slid out of the shafts either because they were oversized or you didnt tighten them. Sanding the motor shafts helps a lot too. Your cables broke as you didn't bolt them to the Y carriage or used poor cables. Two motor Z axis is much easier to maintain then the original mendel one, if you would built original mendel, you would know. That thing sucked to calibrate. The x axis wobble is true, but during prints it wasn't affecting the quality too much. ...
Anyway, keep up the good work.