so is your idea to use this for processing an acoustic drum kit?
I think it might be a good idea to start with a single channel, add some effects and then add channels...
so there seems to be stuff missing - filters, effects, modulation sources, utilities that are needed to get the best out of them...
take a look at my signature - substitute mic input for sound source and spend a decent amount of time thinking long and hard about it...
also spend at least the same time thinking about using a regular outboard mixer and some effects pedals and or rack effects... or a multi-channel audio interface and a laptop - both will get you most of the way to where you appear to want to go for a lot less money...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities