Game Input MultipleXer

If target console is X360, X360 wired controller is required. I'm not sure if Logic3 Afterglow Gamepad works or not.

Thanks for that

Bus 001 Device 003: ID 0e6f:0213 Logic3 Afterglow Gamepad for Xbox 360

On wiki, we used a genuine wired 360 controller.
I think you need to remap buttons in gimx-config.

If I were you, I would have tried another controller and cable.

I wonder if it's because the controller I've got connected to my PC via USB should not be connected to the PS4 also?

I've used gimx and ps4 with only one controller, no trouble at all.

I think there is no such thing like that. You must reupload firmware which suit your usage.

I think UART side is starting fault. Try with another one to make sure.

Your firmware is wrong (G29 PS4). You need to reupload firmware to EMUPS4 to use mouse and keyboard.

For remap wheel: open gimx-config, select Type / G29 PS4. Then switch to Axis tab, click Auto Detect then rotate your wheel. Select Wheel in Axis list box, click Add. Click File / Save and you're done. You should also recheck device list and delete other wheels device, make sure only 1 remain. Is th...

I don't think not changing wheel rotation range is the reason why gimx did not detect wheel.
Try remap wheel again with gimx-config, and I think you should reinstall Thrustmaster driver for windows.

Yes and yes.
You need PS button pressed to activate mouse and keyboard.