I agree with Mr. Ultrafitimes, forget about input settings, they have nothing to do with this. Input settings matter if you are feeding a signal into the computer. You are not so these settings are irrelevant.
You are correct that you can only choose to view either input or output properties in Audio Midi Setup at one time, but that doesn't mean that you have no output when you select input or that the input settings affect the output. It is confusing because when you select input properties the output is grayed out and it says "output is not supported." I don't know why they did that but it only means you can't change settings for the output unless you select properties for output.
You are correct that you can only choose to view either input or output properties in Audio Midi Setup at one time, but that doesn't mean that you have no output when you select input or that the input settings affect the output. It is confusing because when you select input properties the output is grayed out and it says "output is not supported." I don't know why they did that but it only means you can't change settings for the output unless you select properties for output.