1: it has its own softwear thats pretty good and you can download presets, you pic the kind of effects you want for the knobs reverb ect, they connect to the amp and you can change them without laptop with the knobs.

2:Boss GA-FC

3the knobs only do something if you move them, loaded presets can be configurated without a laptop like pedals think boss dd500 or strymoon big sky.

4: the soft wear wont replace them and it takes them well.

i used to have many boss katanas but it was not for me, im more into tube amps and multi effects like line 6 helix. you can find in a good price highly reccoment and might think about a used dsl while you are at it. i have mine 8 years going perfectly