Diesel Bombers - I need specific answers on 0093 code.

Seems like you guys are more direct with your answers than some of the other forums and hope you can help me.
I know this is a common ?? but after searching and reading 10pgs taday and several others. I don't have time to keep reading the same thing.
Started getting the code(mainly 0093 and other codes off and on) on a daily bases after driving 50 miles then up a hill and would throw it every time, if I varied the throttle a certain way I could keep it from kicking, then it got worse. (Yes, changed all filters many times). Then ran it on a high dollar injection cleaning system and it gained power but started smoking at idle(pretty bad). took it in and had a balance test done on the injectors and #7 was over fueling at -7.8 +or-. 4 cylinders where 0.00 and the others where barely within spec on the plus side. Changed all 8 injectors and after 70miles it throw the code and the balance rates where +or- 1.0 except for one that was -2.0. But still in spec and should not have thrown code.
Scratched my head and fooled around with checking for fuel block or leak, (stupid) So I became a FASS dealer and installed a platinum series 150gph lift pump. Starts maybe a tiny bit quicker but throws the code faster than before. It had been getting progressively worse throwing the code quicker and quicker, Now I can warm it up and go full throttle and it will throw it before I hit the governor, and it feels like less power after it shift to high gear, still gains but not very fast. My old 6.5 will out run it by 8mph in the 1/4. The CP3 (the last time checked) would build 15,999 pressure on a gm tech II scanner. When it was forced up that high it ran rough but wouldn't go higher. demand was 22000.
So is it the fprv, cp3, or fpr/fca. Is there a way to test these individually, and manually(I've heard there was) There also is a slight lope in the idle(very slight) sounds like maybe 100rpm or less if you listen to the exhaust but not the engine, the rpm gauge doesn't move. Where do I go from here. I would like to just shim the fprv. then throw in a fpr but the CP3 comes with a new fpr for $850 so it would be a waste to do the fpr then the CP3. Or is it the FP sensor??? If I tear into it I would like just do it once rather than 3 times if all need replaced. Help and what would you do.
Any good gauges you can install to monitor the pressure in different locations to pinpoint the problem.
I also have 4 more duramax's that showed up at a friend shop all throwing fuel related codes,(the one(01 duramax) will build 23,000 and we are thinking its the fprv or could benefit from a tune to open the paramiters) We are trying to get it figured out to help us and others because the local diesel only shops and dealers just throw your money at it rather than get detailed with testing.

Thanks for any help, again sorry for not having the time to read all the info posted on this. If there are threads that would help and you could give me a link I would be grateful.