Ill address the easy ones
1. I ran a bottle of heat through the last tank of gas. (after reading your suggestion)
2. my last tank of gas was shell 93 i didnt notice any difference. Exxon IS a top tier fuel. On this one though, if the difference between top tier fuels is enough for it to pull boost. I dont feel safe running it.
3. Spark plugs were replaced last summer before the hilton tune. Gap was verified several times, and adjusted. Ive only put about 5000 miles on the car since then. I also have the 1 step colder plugs coming monday I will give those a shot, make sure they are gapped etc.
4. The PCV was replaced shortly after i bought the car. It had the death squeal. ROughly about 20k miles ago. Noises have never returned.
For the Boost readings, I know thats only what the ECU thinks is being read since the TDI is essentially lying too it. My thoughts though, are that 8PSI seems awfully low for the eCU to be seeing. Compared to the 12 at mode 4. (again fake reading) If i understand how the TDI works correctly. It under reports boost to trick the engine into requesting more from the Turbo. Thats why i am curious to see what You or somone else sees the ECU report at wot. If its higher by a considerable margin, then my car may be either pulling boost, or having a boost leak.
The car does have 115k miles on it, so i certainly wont rule out the DV. Viva makes an upgraded OEM model, that i will probably just buy.
The other area i could see myself having an issue is with the Intercooler piping. I didnt replace it when i put it on. Also with the Oil leaks the car had, its possible some of the houses could be damaged. I know there was a good ammount of oil on the Hose coming from the turbo.
as for the Coil packs. I think I am just going to go ahead and replace them. I had my thoughts about them last summer, in VWs its common for coils to fail with increased boost (on older cars).
Adding in mods: IPD Turbo back, d088 FMIC, K&N drop in, powerflex mount insert. (those are the ones that matter anyway)
Also i realize I didnt address the snab. I had a snabb intake when i was working with hilton. Didnt seem to make any difference to the car aside from noise.