Writing user manuals is very time consumpting work. To be honest nobody like these work, but we are writing them to help customers. So, please READ USER MANUAL. It is not very hard and we put a lot of efforts in them. In the same table at the bottom line, you have explanation for these: "NC.= not connected" Simple?
PoKeys is not only keyboard emulator. Normally you are using PoKeys as an HID IO device which is very reliable. There are no reports about issues which you "heard". If PoKeys does not have enough IOs, you can add aditional outputs with PoExtbus devices.