Are there tunes that just keep the EGR closed or minimize it's use? Or it there an advantage to eliminating it? Do the EGR delete kits block it off or remove it from system? Once it is deleted do I need a tune to see a power/efficiency improvement?
Also do the upgraded FICM mimic what tuning does or do they control different variables. It looks like injectors might be in my near future, do 155 or 175 injectors improve power on a stock engine? Any rebuilt injectors recommended or ones to stay away from?
Going with a custom tuned SCT, you can run the EGR valve any way you prefer.
The advantage to a block or deletion of the cooler is that the valve cannot be forced open by back pressure, and the cooler can't fail following an clogged oil cooler (leading to the 6.0L HG failure).
If you run a block or deletion, you will need a tune on the later 6.0L's which will throw a CEL without flow through the cooler.
As for the FICM question, this gets complicated as we start talking about matching FICM tuning with PCM tuning. The early high voltage FICMs were in fact a bandage for the issues surrounding the longevity of these modules. I feel that Bullet Proof Diesel, solved that and the high voltage units are no longer nessacary. The tuning of the FICM is a different set of variables that that of PCM tuning, and when matched together will cancel eachother out. (I.E. a 100HP FICM tune with a 140HP PCM race file won't produce a truck in the 510RWHP range, but closer to that of 420-440RWHP). Getting the tunes matched up ususally requires an FICM file in the +25-40HP range, depending on your injector setup and fuel pressure regulation.
For you injectors, unless you are going to need to replace them anyway, I'd start with a new turbocharger first. For example a MadTurboWerks (MTW) Stage 1 or Hybrid. Stepping up to 155 or 175 injectors will allow you to lay all the supporting mods in the truck first and be able to take full advantage of those injectors when installed. Personnally, I feel the truck runs smokey and hot enough under stock injectors and turbo, and will be doing a turbo first on my own build.