Looks a lot like the Summit cell I just got. IIRC, The foam prevents sloshing and prevents air bubbles in the fuel. People also have run cut up oil containers, peices of PVC pipe, lots of things will work. It seems there are mixed feelings about the foam around here, so I'm going to try it and see how it does. I figgure I allready have it and can always remove it if it causes problems. I'm going to run a pre-filter before my pump, just in case.
I'm not going to worry too much about starvation. My cell has a sump, and I'm planning to keep it nice and full on the trail. The baffling helps keep the sump submerged as well. I may angle the cell slightly toward the sump just to be nice to the pump.
Only two holes? Sheesh, I got 4 and have to plug one. You could drill a hole and install a fitting I suppose. I'm going to connect supply (sump), return (top), and EVAP vent (top). I have an extra fitting on the sump for supply I'm just going to put a cap on. Does one of your top holes have a pickup going to the bottom? If not, I would think your cell was not built correctly and is missing the supply port on the bottom. I would call whoever you bought it from and ask them what the deal is. It may be a defective cell.