To be honest I have no idea why you are having so many problems this literally just worked for me without any problem at all. The config is tied together, I know you can change things independently in OBS but if you start the Elgato software everything gets set back.
What driver do you have installed for your device? Go to Device manager, right click Computer, Manage, Device Manager and drill down to Sound, Video, and Game Controllers. Right click on Game Capture HD60 Pro and choose the Driver tab. Mine looks like this:
View attachment 13550
So my driver version is 1.1.0.160.