Re your 1st question - see Main Manual 8.5, chapter "Technical Specifications", pages 354 -359. You can download Main Manual from the Kemper web.
I have looked at the manual and i couldn’t find out whether those 1/4 inch outputs that reside next to the main XLR outputs where balanced or unbalanced. It also does not confirm these 4 outputs can be utilized at the same time which was another question I had about a month ago and somebody on here said yes you could run all of them at the same time. Maybe I missed something I don’t know.