Hey Lou, I'm certainly no expert but I think I can answer at least one of your questions.
You asked "I have arbitrarily decided that every 2-3 pounds of pellets converts to a pound or so of bluegill, but is there a scientifically determined estimate?"
From my research I see time and time again that 2 lb of feed translates into one pound of weight gain for bluegills and cats.
I noticed you said you feed 4 gallons a day. Is it a liquid food?
I envy the fact that ya'll are catching a number of bass in the 2-5 lb range. Sounds like you're doing pretty good

roadtrip