Jim, thanks for your ideas above, those are super helpful and interesting! Good food for thought, I will mull this over some more.
I find particularly interesting and useful your comments i) "modulation and utility should take up about 50% of the rack" ii) "matrix mixers are a great way of expanding modulation sources" and iii) "I'm in the use fewer modulation sources and more utilities to get more, complex modulation camp" -- great advice for a newbie like me!
Any additional folks from the forum want to add to the thread? (Hope so!)
Thanks all! Nicholas