jd, considering your location in KY, an 8' depth will be enough to help fish survive under ice and avoid a winter kill. Like was said earlier, cleaning muck may be a lot more expensive than adding a good aeration system. Aeration can help your water quality improve for that "clean enough to swim" goal as well...though in reality, the water is usually safe regardless of the looks.
What size trees did you remove? Trees over 4" diameter chest high are often best left alone. If the drip line of the trees extended over the water, the roots will be in the water also. removing the tree could cause leaks as the root system decays.
