I called my "guy" yesterday, and he is out on vacation until Nov 14!! (hunting season, I should have seen that coming!)
--- damn; there goes my other pool/deadline.
"But when he comes back we are moving forward. His recommendation is to pile the dirt up instead of trying to redistribute it to avoid a giant mess. So my pond will look pretty shoddy with a giant pile of mud next to it for the next 4 months! But getting it up and running for my ducks is the primary goal, so we will have to deal with the eye sore for a while."
--- have him berm the sides as you'll want something in the end to keep runoff from getting into your pond and you might even landscape it; it's what I did.
"Also, quick aside: if my pond contains 1750 gallons, and my bog is 600 gallons (before filling with gravel) -- do I get a pump that is sized for 1750gph or 2350gph? I am assuming bog filtration requires turning over the water in the whole pond once per hour.
(recommendations for pump brand greatly appreciated!)"
--- better too much than not enough; general rule of thumb for average for pond turnover is 1-1/2 times per hour but the bog is a bit different. Many push a lot at fast speeds and some push less at slower speeds. It doesn't seem to make a lot of difference re the ponders success. I'd opt for slower just to give the plants and bacteria a chance to do more. I use a Dayton pump. Actually, I have two as redundancy with a pond is real valuable!