Almost. The PS pin is either high or low and is a switch/input for the ECU idle up. That needs to be a DI for the Link. 
The PSCT is the output (most likely an AUX from the Link) that is then sent to the PS ECU to switch off above x kph as you suggest. That's the way I understand it. The beauty of that is we can control what that switch condition is now. I believe that it needs to be grounded (low) to switch off the pump. Thankfully, this is exactly what the AUX does.

So I could use Speed value on Aux 7, 6 or 4 I think for PSCT and Anvlot 1 to PS or Inj 5 to PS.

The Aux I think is correct, but the AnVolt is a 0-5v input. Not sure if it would acheive the same thing as having it wired to a digital input (DI). I certainly wouldn't wire it to AnVolt.

Did you set up knock control? If yes did you use the factory one or Gm one etc?

Technically yes. Factory sensor. The KNK pin on the Link uses the factory pin location but the documentation has that blank. Apparently it's been fixed in the latest release.

I still haven't configured the knock threshold though, so it really isn't active.