I personally like tesseract tex-mix... it's expandable and inexpensive... but do your research... some people claim there's a lot of bleed and a high noise floor, nothing I've particularly noticed though...
maths is a fantastic module - but it only really comes into it's own when you dig really deep into it...
bigger rack warts - you have used the tiptop uZeus in your rack - if you are using a RackBrute you should be using the Arturia power supply modules (rack warts - they steal racks space and are ugly) https://www.modulargrid.net/e/arturia-rackbrute-6u-3u-power
as for a case being able to power whatever you put in there - hahahahaha - no.
you need to add up per power supply the draw for each rail from the modules and compare it to what the manufacturer states is the maximum draw for each rail - leave at least 25-30% headroom... if not there's always a chance your power supply either shuts itself off, a module fails to power on or, possibly, the power supply decides to die on you...
"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