Jadog,

They are giving you good advice not to worry about those plants. Those are terrestrial plants. They should all die after they are flooded as your pond fills.

If they are in the swimming area, then definitely mow them now. I would let the rest of the weeds go.

You might also consider adding Eastern Mosquitofish (Gambusia holbrooki) to your pond now. They are a minnow that is native to your area and they will keep your mosquito population down so your family will be able to enjoy the pond area without being covered in DEET!

Good luck with your big pond!