I see a couple things...
First, the center compartment, being that the opening to the return (left) compartment is located so far up, may develop dead spots in the bottom, and all that water down there isn't serving much purpose. If I were you, I'd locate the opening at the very bottom of that baffle. That effectively increases your sump capacity, because the water can evaporate and drop the levels down over this whole area.
Second, depending on how much flow you have, you may have trouble moving all that water through the drip plate and down over that media. You may need to put a valve in the right hand baffle near the bottom to allow for a certain amount of bypass.
Last thought (not necessarily a problem, just a heads up). Make sure the water level you are planning in that skimmer compartment is within the specs listed for that skimmer. Most won't operate right if the water level they are sitting in is too high or too low.