Let's start with some pictures to try and clear up the function of the fuel system.
Both images and a lot of the information comes from here: http://www.aa1car.com/library/returnless_efi.htm
There are two main types of Electronic Fuel Injection (EFI) systems. The return type, and the returnless type. In the return type, excess fuel is pumped to the fuel rail, and intake vacuum is used to regulate the pressure, and excess fuel is returned to the tank. In a returnless system the filter and regulator are often part of the pump assembly and are either inline, or submersed in the fuel. Sounds like yours is submersed in the fuel. The article talks about most modern cars, and your's would be included, are returnless systems. You would need to check the book on yours to find out for sure which your car uses.
Note that in both systems, the tank is not something in two halves, it's one large tank. There is no movement of fuel from one side of the tank to the other. Fuel tanks on street cars are generally one large tank. There may be systems (like baffles) that help prevent sloshing of the fuel, but there is one fuel pickup near the bottom of the tank, and if it's a return system, a single return. Nothing to move it back and forth across two halves of the tank.
Two things that may help you in finding the problem. First is that while research may show the common failures if your testing shows those systems to work well, then your cars fault lies elsewhere. Second, the other big difference between carbureted fuel systems and fuel injected systems is the fuel pressure. An injected car typically runs between 30 to 60 psi, much higher than the 6 to 8 psi for a carbureted car. You need to check the book on your car to see what the normal pressure should be. Your pump may move fuel, but if the pressure is way below where it should be, the car may not start.
Next, don't focus entirely on fuel. If your testing shows that the fuel system is delivering the right pressure, and the injectors are not clogged (which seems likely since they should generally not all fail at once) your problem is not fuel. Check for spark on each cylinder, and see if you are getting any.
I would also suggest using a scanner to see if the ECU is throwing any fault codes. If the check engine light is on, you will certainly find codes when you scan for them. That will also help diagnose the problem.
Hope that helps!