One, what is the best way to get audio from a Mac? I have the monitor output from the Mac converted to HDMI, but of course that does not carry audio. USB DAC seems to be the way? To optical? I assume I can assign that to the HDMI input that the Mac Mini is using?
A USB DAC will output an analog signal. If the Mac has an optical output, you could use that.
Also the analog input config is a little confusing. Can I only have ONE analog input on this system? This is how it appears with the input menu.
No, you can use multiple stereo analog inputs. Each source has a stereo analog input that it can use. There
are some separate menu items for the 7.1 analog input (there's only one of those) and the XLR stereo analog input (there's only one of those, as well), but those are special cases.