to me there seems to be a lack of filters, effects and utilities...
I'd want at least a reverb, delay and a few more filters... and I can hear you saying "I do those out of the rack" but... applying delays and reverbs early in the chain can work very well...
as for utilities - a matrix mixer (the king of mixers imo) can make limited modulation go a lot further and in much more interesting ways... also some extra attenuverters/offsets would help...
as for layout - I like from top to bottom/left to right:
sound sources, modulation sources, sound modifiers, control - with utilities spread throughout
"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