Allan, speaking on flounder in particular: I often used to fish a particular bay/estuary area that had some flounder in it, but this is when I was a cheating spin-fisherman... nevertheless, sometimes working a deeper jig flounder would take an interest. Since they are such a flat fish, they can turn their body like a jack, pompano, or permit and put some power into the fight if they're feeling inspired. If you work a crustacean imitation or even a minnow across the bottom, you're likely to take a flounder or two. It helps that they are tasty and easily filleted... I can't help with the shad, but I wonder if fishing for them is anything like pinfish in Florida, which is more of a battle of keeping them OFF your hook.
Working out a way to convince my university to allow me to hold my TA office hours on the nearby creek...