The suggestion to start with a few devices to get started is valid - most people don't start a MIDI system with as much gear as you have. Hook up you mixing board to your power amp - to whatever monitor speakers you use .........and then hook up one keyboard/module at a time.
To tame the MIDI issue - you could use some MIDI routers - I use a couple of 2 in 8 out that keeps things more organized and avoids the MIDI delay caused by daisy chaining multiple devices.
However, if you have 5 K1000s and a K1200 - that is 96 channels of possible MIDI (not counting other equipment in your system). Unless you are composing some amazing film scores ........ do you really need that many sound modules ......... which all can generate the same sounds?
In my studio, I have 2 keyboards, 7 sound modules and 3 smaplers - I trigger MIDI from both keyboards, from a guitar and from a MIDI drum module ......... and I have numerous MIDI controlled effects devices. Do I have 4 MIDI ins and about 36 MIDI outs.......so ..... I fully understand how complex your set-up can be.
But each sound module I use is different, most from different manufacturers - and I use select sounds from each (sounds the other can't do). I would never have 5 of the same module (unless I got a hell of a deal when I bought them)
Limiting the number of redundant modules could make your set-up much easier.
