Very interesting post, and I would like to learn more about your experiences with this install.
I have one concern regarding your list of upsides... As a 1/2 acre pond with decent depth contains what, close to a million gallons, do you think 35 GPM will make much of a dent in times of drought?
Running 24/7, it would take 438 days to provide a million gallons. (unless my math sucks, always possible)