Others may have better ideas, but I'll throw all this out.
The shoreline slope is pretty steep, so control of that would be my first priority. Just looking at the pics, the eroded bank is less than a foot high, so bulkhead installers would probably want to make them higher, and then back fill them to level out the banks.That means heavy equipment on a nice bank side turf. Rip rap, even if a fabric mat is placed below it, will eventually have weeds, and spraying them will create a brown dead collar around the pond.
Let others jump in, but what I've done here and has worked really well, is to go with a base layer of concrete bags that can be staked to the pond bottom with rebar, and leave about 4" of that rebar exposed so that the next layer won't move when added. The concrete bags may not be the move elegant solution, but I've done several that are 3-4' high, and have had zero issues with them. The paper on the bags will eventually sluff off. Using some kind of pressure treated lumber for a retaining wall would work, but at some point it's going to rot, and would need to be replaced or maintained. Lot's of lakes around here, and the wooden retaining walls really look bad after aging a few years. I'm not sure the chemicals in the wood are good for the pond either.
