How long has this lake been established? Most likely it already has a full assemblage of zooplankton and inverts. Most, if not all, inverts have a flying adult stage that colonizes new water. Take a fine meshed net, about 1mm, and scoop up some mud of the bottom. Don't go in to shallow of water were wave action can bury the bugs. You will probably see alot of bugs in the muck, if not then maybe I would look into stocking. If you had a finer mesh net you could sample zooplankton too. It would probably be difficult to establish any bugs with your abundant forage fish.
Your skiny perch could be a result of a big YP spawn. Adding walleye should thin the YP, and improve your RWs.
