Fuel pressure dropping while driving and under acceleration to zero at idle runs 4 lb electric Blue

If this was my car, I would:
1. Check voltage and electrical connections to the pump for resistance. How does the ground look? I see a butt splice and those trap moisture and corrode. Hell I think they corrode before you crimp them.
2. Remove all suction side restrictions to the pump and retest pressure.
3. The full stock fuel system should work great up until it vapor locks, at which point you could add a restricted bleed back to the tank. Simple and it works.
4. That crimp bend in your exhaust over the axle looks like a restriction that might make your engine run hotter. Might just be the camera angle :)