On Saturday, 2017-09-23 I picked up MH Magazine ($49) as a backbone theme for the future site.
First problem was: I did not see any Home areas (Home 1, Home 2, Home 3 etc.) in Customize –> Widgets area. The solution turned out to be – I forgot to signify my home page with a template –> Homepage (see image.)
So MH Magazine support already worked for me, and I relatively quickly found the answer.
To use “Multiple Categories Filter by ID:” and exclude category use minus (-) sign. For example, to exclude category 123, put -123 in Multiple Categories Filter by ID:.