I was wondering primarily about whether or not you could have a complete loss of the pond at some point. Glad to hear that you won't.
I think that a lowering water level wouldn't be a great detriment to spawning success. I'm just guessing here, based on some ponds that I know of that have had good year classes during years with significant loss of water. Keep in mind that spawning success is less about nesting areas, and more about availability of appropriately sized forage items after hatching.
You'll be fine when it comes to recruitment, I'm betting.
Holding a redear sunfish is like running with scissors.
