The maf is to close to the turbo. Even after you pull to a stop that turbo is spinning 30K rpm. If you want to run maf, then you are going to need an 83mm maf pipe and it needs to be in the fender far from the turbo.
As for the pump. All of that depends on how much power the car makes once you fix it. But here on the dyno that has no correction factor added in with full loaders, A walbro only gets you 400 whp. A dw340 gets you 450 to 500 range and past that, you need lines and a relay with direct power feed. At 500 to 550 you need TWO pumps or a walbro 400 or walbro 460, lines, direct power feed and ID2000s. to run 600whp.
I would start listening to these guys and get the car fixed. You already posted you wasted 4 months. Now is not the time to start questioning what these people are telling you