I've been out brush hogging for the last 3 hours, so my mind had lots of time to wander and wonder.
Has anyone at your pond kept a "creel survey" of size and quantity of catches -- those caught and released, and those that were kept? This goes for bass and bluegill.
Of the bass you released, how many were deeply hooked, and did you only handle the released fish by their lips? Catching 35-50 fish per hour, if mishandled, could result in pretty high mortality.
As for bass doing damage to the bluegill population, over 50 years of fishing experience in impoundments from about a half-acre to about 80 acres, makes me think that is not possible. Big fat bluegill are generally the biggest consequence of the bass eating too many bluegill. But, not culling the right size bass, or over-fishing the bass, can quickly unbalance a pond population.
Ken
P.S. Those of us who were around in 1959 know about "kookie." We even had our own Top 50 hit about Kookie! Songs like this just don't come around anymore.
Kookie, Kookie, Lend Me Your Comb! 
