Fuel pump failures in later-model MasterCrafts are a pretty well-known phenomenon across the industry, and especially on this discussion forum. As a "victim" myself, I congratulate you on taking this on and appreciate the photographic step-by-step.
I recall that GM had problems with their in-tank fuel pumps years ago, but I don't know the specific problem. I assume they use Carter pumps. I've owned GM trucks for many years and I've never heard of any recalls - at least not for any vehicle I've owned. I did have a trouble code on a previous truck that was read as failure to maintain pressure, and I was told it was due to a leaking internal valve. I tightened the gas cap, had them clear the code, and basically ignored the problem. It never recurred in 30,000 additional miles.
Having dissected your fuel pump, what is your opinion of the oft-proposed mechanism of failure that fuel is only filtered below 1/4 tank and that if/when the filter plugs up, failure to pump cooling fuel is the reason for failure? Were you able to detect such an arrangement?
'04 MariStar 230VRS/MCX