Fmpnd, it sounds like you've got your ducks in a row.
About the only things remaining to consider might be:
o An industrial grade service panel (perhaps silver bus).
o Cryo-treated dedicated lines (I had Cryo-Nebraska double-cryo 500 ft. of 10 gauge).
BTW, proper line conditioning should negate any concern for noisy AC appliances being on the same or opposing leg/phase.
Most important consideration may be protecting your components from bi-directional digital noise induced through the AC lines by cdps, DACs, computers, digital amps, etc.. This digital noise will make its way back from the source to the service panel and then into your dedicated lines. The only way I know to treat this is proper line conditioning that includes bi-directional filtering (which also keeps digital noise from going back into the wall and inducing sonic harm elsewhere).
-IMO