As I mentioned mike, I think running your overflow to the skimmer only would restrict the flow and could at sometime cause a tank overflow? How about adding a "T" to it and feeding part raw water to the skimmer and the rest to the sump.
You could just use the sump exit part, as a back up/overflow port and the bulk could go to the skimmer. Some detritous would still get to the sump, as it would passing through the skimmer anyways but at least it would be raw water.
Just a thought anywho, as I have never done that, owning only large becketts with their honkin pumps.
