1. Do you need to replenish the developer or is it sufficient to just add back what is lost during processing?

"I am confused about #1, do you mean just add water, or add more PO to make up for the loss in process? I add back more PO once my jars get too low. I keep 5 one gal solutions with varying concentrations of pot dichromate, once they get to about 2 liters I add more PO solution."

You answered my question. When working in kallitype with sodium citrate I typically keep on hand several bottles of developer with varying concentrations of potassium dichromate, but as it is used up in processing I regulary top off the developer with a fresh sodium citrate solution of the same strength as the developer, plus a few drops of dichromate as needed. If you don't replenish regulary with kallitype the prints become very hard, and eventually impossible, to clear. I assume from your answer that it is not necessary to replenish on a regular basis with pt/pd printing to clear well.