I have always keep my pump running all year long but am thinking of removing it this winter.I live in central Ohio and the pond is about 4-5 foot deep in the center. Naturally this is where all the koi spend the winter. Any pros? Cons?

It depends on the winter. If you remove the pump remember to disconnect at the pipe not at the pump. With koi you will need aeration and a deicer. Purchase those from the store.