Well, sharp was right; had to drop it again, and found that the connector was faulty from the factory (the new one). Tied to get it as it's supposed to be, but no joy. I ended up using the old plug and splicing it to the new sending unit with some water proof solder splices that I bought some time ago (between the solder, the tied cables, and the tight grip and glue of the water proof splicers, I am betting they will end up being stronger than the plug itself!). This did not fix the pulsating fuel pressure, so I checked vacuum and vacuum was fairly stable, so I tried the stock FPR; there is still SOME oscillation, but not nearly as much (3 PSI more or less, versus 10 or so before). The odd thing is that when the engine is cold, the adjustable FPR works fine, but after a while, it starts acting up. My guess would be that there is some resonating frequency which is causing the FPR to go into a harmonic oscillation, or something... I'll post the videos later on after they upload...
The good news is that the Jeep is up and running; took it for a test drive, and no ill manners were detected. Starts right up after shutting it down also, and no fuel smell found. I am still loosing fuel pressure when I shut down, though, so there is a leak SOMEWHERE... Plus, I still have to install the eFan controller box...