1) Are you sure that all of the modules you've selected are either in production or are currently available? I'm going to bet that the answer there is 'no'. Also, have you confirmed the depths required? Note that the RackBrute does have internal obstructions in the row that your power supply is located under, and that it's a very good idea to leave about a centimeter for your ribbons and connectors on the bus board.
2) Have you tried to minimize the 'real estate' occupied by your modules? These are fairly small cabs, with only 88 hp per row. If you can find any modules to shrink (and I see a few right off the bat), do so. In builds like this, it's best also to see if you can actually dispense with certain modules altogether, such as mults (use inline ones) or jam as many functions as possible into as small a footprint as you can.
3) Do you really need 15 discrete attenuators? Don't try to convince me that it's a good thing that they can also mix, because you've also got two 4->1 mixers as well besides the Befaco Hex setup. Remember, most modules that're worth a damn have input attenuator/scaling pots...or they should. The Erogenous Tones one is a killer device, given how flexible it can be. As for the rest...uhhhh...kinda scratching my head here...
4) Never put in a big blank panel when working a build out on MG. Doing this also puts the same big blank panel in your head as far as future builds are concerned. When working out a final build version here, work it out 100%...you can always go back and swap things around/in/out later on. This isn't a test. You can do this over and over (and SHOULD) until you've honed down a real, serious, no-foolin' final build. Especially if you're just starting out in hardware in general, to say nothing of modular itself.
5) Finally...do you actually need to do this in this way? Consider: you're transitioning from an 'in the box' synthesis environment where everything pretty much works within the same operational paradigm to perhaps the most complex form of analog synthesis out there. It's sort of like going from driving a Prius to a Ferrari 488 Spider with no sort of transition in between. Also sort of like that in monetary outlay, too. Sure, these things look cool...BUT...they cost, they require some degree of hardware electronics knowledge, it's possible to make mistakes that can cost hundreds of dollars (or worse) in mere milliseconds, and you need to know how analog synthesis signal flowpaths function (and how they function on your specific instrument) like the back of your hand.
My suggestion is this: stop. Step back, take a few deep breaths. Start at a better and more sensible start-point with hardware than this. If you want "something that can produce leads, bass, drums with easy control for modulation," modular might be a good bit more than you're anticipating. I mean...look at your build above. Does that look like it has the sort of "easy control" you're looking for? Especially when you start interconnecting that with a Mini 2S? My guess there is that, no, it doesn't...mainly because, no, it doesn't!
Do yourself and your credit cards a favor for now, and look into some dedicated devices. Certainly among those, include one or two patchables, which are the best way to sort out what modular does, what it's good for, what it's NOT good for, and how you specifically want/need to use it. This is the real way to transition out of a pure software environment, and in the long run, you're apt to get a lot more done over the long term by doing this than if you plunged right into the deep end of the pool straightaway. Doing the latter will likely be an exercise in frustration, and you'll end up more perplexed about the point of modular than before you started.