Aluminium Profile Type Router - Initial questions

[CNCRY]

Very mixed day of results - finished most of the Z axis strengthen plates and connected the 2 Y motors up.
I ran each motor individually first with the ballnut uncoupled to check how it runs. The good part
The gantry motion on rails is very smooth and all good, and one ballscrew is running true (until squaring anyway!)
Using a digital square the gantry seems good enough to progress to cutting a square to determine further.
The bad bit - the other ballscrew is definitely bent, not 100% if it arrived that way but much more likely it's a result of drill testing or something else I did! Some swearing involved and am waiting to find out if Fred can amend my spindle order...
Advice for anyone in the research stage - plan some budget for screw ups!
I connected both screws up for a short time just to test the Axis slaving - and it was cool to see my creation moving via the laptop finally!

Now waiting on replacement parts I'm going to fit and wire in the limit switches. This should be simple but the diagram which came with the switch confused me..
Can someone tell me is this right? I thought I understood it until I see the black cable on the switch diagram shows 6-36V while "out" on the AXXB manual shows it at 0v?

AXXB manual image, switch diagram and my understanding of it.