Well you can remove them completely, just have to put vent somewhere else. I believe it is the same cavity as the 3/4 panels, so anywhere there is fine.
Still mount the pump by the tank, put a fuel filter before the pump, and you don't have to run a return, it's just optimal to do so. Repco do an aftermarket low pressure fuel pump, if you are looking.
4 PSI is plenty enough pressure, it should be mounted by the fuel tank, preferably with a restricted return line. it should be wired to the ignition swith through a relay, you can also include an isolating switch if you so wish. Although the factory mechanical fuel pump delivers plenty enough fuel for a road car on webers.