Symptoms of bad fuel pump regulator ?

or maybe I should have titled this: do I even need a fuel pump regulator ?

let me back up a minute

I used to have an electric fuel pump, but even after trying it in a few different places and a couple other things to silence it down, we finally ripped it out and replaced with it a mechanical one

What would happen if we left the fuel pump regulator in place (in case I want to switch back to an electric pump later) ??

What would be some symptoms of a bad fuel pump regulator ? For example - in my situation - what affect could it have on the flow of fuel to my mechanical pump ?

TIA

In theory it could only do one of 2 things either not regulate the psi at all allowing the carb to flood or restrict the flow at some/any psi. Havent been inside one so dont know if #2 is even mechanically possible.

thanks for the info