windows 7 and windows 10 64bit, YES but only with a usb signal generator. no printer port drivers. I have done it many times
usb 2 yes
usb3 should be backwards compatible, no speed increase,
cable, keep it short. standard cable length RF noise can creep in causing Estops
Post a pic of the control box for your router, but normally they are very low quality, I would have to see your XML to see if the spindle is setup.
The roadrunner gcode is in inches so the feedrate commands are going to be very slow on a metric setup machine. Ohh and the roadrunner is going to be very small. The gcode for the roadrunner is for a large format router and will crash your small one.
using the MDI line you can type in m03 s5000 and see if that starts your spindle. BTW that is a zero not a O. M05 should turn it off if it does come on. The M03 command has to be at the top of the gcode and m05 at the bottom.
Hope this helps.