I'll add my two cents here on skimmers - I've seen ponds with and without and have learned that a skimmer does more than just remove the debris you can see and scoop from the pond. To me, the surface of a pond that's being constantly skimmed sparkles in a way a skimmer-less pond doesn't. All the microscopic dust and debris that falls from the sky and settles on the pond surface is constantly being swept away rather than floating until it finally sinks. It may not add much to the overall cleanliness of the pond, but to me the aesthetics are definitely different.
Just another opinion. I also aesthetically prefer not seeing a lot of mechanicals in my pond. I know it's manmade, but the less of the working parts I can see the more I can maintain my illusions!