You should probably put the baffles much closer to the tank drain/skimmer area. You want three baffles; over/under/over and then as large an area as possible after the baffles. This way your area of evaporation is much larger and your sump water level won't go down as quickly. You'll also have water moving slowly through the area after the baffles which will allow small bubbles to rise to the surface before they get caught in your pump. As far as the fuge goes, can you tee off the tank drain and divert some of that water to the fuge? Then you can drain the fuge into the sump just before the baffles, or just after if it's a nice slow flow. I'd try to avoid using a sponge filter in your bafffles. It won't really do anything except trap detritus and very small animals from the fuge.