Welcome to the forum!
My sole purpose for fishing is to enjoy with family and have been debating on bluegill, red ears, or crappie. My favorite fish is crappie, but everything I read says not to stock with them. Is there a concern with not being able to remove enough of them or crappie eating other species?
To answer your question, yes and yes. You will need a predator in there to eat the smaller fish to allow the fish that avoid predation to grow to a size that you can eat. You will have to have a self-sustaining minnow population in the pond to even have a snowballs chance in hades to sustain any crappie.
As for digging the pond in two stages, don't. Plain and simple. Digging the pond small and steep, then going back in to make it bigger and more gradual the following year will cost you probably 2x the dollars than doing it all at once. You will have to deal with wet soupy dirt, you will have to dewater the pond to get the dirt out and to contour it, and a tractor with a pan scraper won't be able to get the dirt once the ground is saturated with water. You'd have to get an excavator and a dump truck or an excavator and that tractor/pan scraper. Plus any fish in there are toast because you have to dewater the pond to dig the 2nd part. You should put Fatheads or Gambusia in the pond for the first year to help control mosquitoes; any game fish put in there the first year will most likely die when you go to dig the 2nd half.
