[vettestr]

A bell went off when you said "(the outlet on the supplied tank is in an "extremely fragile" state due to design. I am afraid to even look at the damn thing.)" What if the connection was allowing air to be pulled into your fuel system on the suction side of the pump?

A couple of thoughts here..... As you know electric pumps do not pull well as they are designed to push. Make sure fittings are sound so air can not be pulled into system. Install a P-Trap in the hose between tank to pump by making hose a little longer and allowing center section to sag. Sorry for description here but I am trying to make a low spot in hose for fuel to stay in so it picks up a prime quicker. Get rid of the filter between tank and pump as this is a huge restriction on a set up with problems already. I think the filter is hurting the prime big time. Regulators do not like air and gas so fixing inlet may resolve that problem. good luck jeff c