A few things immediately come to mind...first up, you should add the "master" module to the Praga. It'll be useful for quite a few things. And yes, add a matrix mixer; in a build of this size and complexity, you've got plenty of sources to screw around with via one of those. Plus, add the expanders for the Batumi and Zadar. You'll want the extra functions.
But the big thing I would change is the organization here. Everything seems to be laid out in a hodgepodge manner, which is definitely going to add to that "overwhelming" sensation. But by putting things together in functional groups, you can cut that problem down to size. Sources...modifiers...modulators...effects...etc, that sort of thing. It also leads to different methods of exploration...for example, if you had the Black Sequencer AND the Moskwa in proximity, you might notice that there's a possibility there that hadn't presented itself before. Same goes for having the logic modules and clock modifiers in proximity, and so on. Yeah, it sounds like a total PITA to do that, but trust me...in the end, the effort's got rewards.