The fuel filter is very effective at keeping water out of the heads/rails - to the point that wet fuel can cause fuel starvation. BTW, the 'issues' with the dead-headed fuel rail are way overblown, save your money here...

It looks and sounds like you primarily have a fuel quality issue. The additives you've been dumping in the tank are now contributing to the problem. All these do is allow the water to get thru the filter and ultimately thru the injectors. This stuff is in the same category as radiator stop leak. If Red Dawn goes down and ya gotta get out of there, do what ya gotta do. Otherwise, pull the radiator - or in this case drop the tank - and do it the right way.

That cloudy fuel is a big, red flag.