Wow snrub, it's tough. I have wondered similar things from the get-go myself. I still don't understand it all either. As you said, that phrase "it all depends" comes in. I wanted to know specifics when I started out, but there are just to many variables, and each of those variables can change from year to year, changing the outcome of each years fish potential. From what I have read during the few short years here, each pond has to be considered individually. There are so many factors that can influence a pond's life cycle.
It seems like an important factor of knowing what to harvest, when to harvest, and how much, is keeping good records of the weights and numbers of fish caught. That, and the other ways to measure the fish conditions, sizes, and populations. With that info the pros here can guide you to what will be best for you. There was a very similar question as yours not to long ago, possibly by Lovinliving?
I think it might have been outdoorlivn I was thinking of:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=347182#Post347182 
