Howdy David,
Sounds like you are almost passing me on this seasons queen rearing.
All your plans sound, right on. Don't forget to regularly check every inch of the combs for rouge queen cells - if you overlook one and she emerges, you will soon know it happened.
I often replace combs where the young bees have already emerged with new combs of emerging brood. I admire your priming the nurse bees with combs of young larvae - that takes a lot of extra effort, but certainly has its rewards.
As soon as a batch of cells are sealed, I usually start the next batch. Always be sure to remove any cells, at least two or three days before they are expected to be ready to emerge - sometimes one will be early, with its disastrous results (you've already prepared for that, harvesting any that reach their tenth day post graft). And you can certainly prime the nurse bees even with a batch of sealed cells still present, I do it all the time.