Diesel Bombers - 04 6.0L Cranks but wont start

Im coming from Powerstroke.org - theres a lot of good info Ive found searching through this site, so I figured I would try my luck over here as well

Truck:
04 6.0L with AFE Stage II, MBRP 4" w/ Cat Delete, ATS Tuner, ATS Torque Converter, Banks Technicooler, and Ispro Gauges. 85K miles mostly running Amsoil Synthetics, and usually the ford diesel additive. The truck sat for about a year while I was overseas - and it was "driven around the block every couple weeks."

Situation:
About a month ago, I started the truck and noticed it took about 2 seconds longer than usual to start. I drove to the grocery store, the truck ran fine (good power, smooth idle), but when I came out of the grocery store it would turn over, but not start. I knew the batteries were about kicked, so I replaced them (out of town, no code reader with me). Still nothing, so I had it towed to a Ford Dealership... Still trying to track down the receipt, but I believe they replaced the ICP (about $500 part), and labor, and they told me all codes were cleared and the truck started/ ran fine. I noticed it took about a second longer to crank than i remembered, but it cranked, so it was good for the time.

Month later (and about 2K miles towing a car hauler across the US) and Im back to not starting. Code reader shows P0404 and P1335 (EGR Open/Malfunction) and P0603 (Programmer). I found the TSB for EGR replacement consistent with the first two codes, but it describes a lack of power/ surge rather than innability to start.

My thoughts/ other facts:
Ill usually run the synthetic for about 7K miles (its close to its next change) - could this be causing an issue with the injectors?
Fuel filters were replaced and Injectors cleaned at about 70K miles, Dealer Service

Any help is appreciated.

Sean