Below is a link to your initial thread (it is an 05 Hydro).
I am just going to be blunt. You had a lot of issues that you probably didn't address.
The low battery voltage killing the FICM was a point of discussion. I don't care if your batteries are "only" two years old ... or even two months old. They can be weak or even bad at any age. No wonder the FICM was an issue and may be an issue again.
The issues of having high coolant temps and "eating" oil were not addressed. The brown coolant may have been addressed with the oil cooler, but usually oil in the coolant will coagulate into a type of "milkshake" color and consistency. If it is only a little oil in the coolant, it will float on top. Neither situation can be accurately described as brown coolant in my mind.
Edit - I re-read your thread. You said there was 100% oil in the coolant. Not sure I totally understand this. The coolant system holds 7 gallons. The oil system only hold 3 1/2. Regardless, you may have run the truck with inadequate oil volume. Some people say that you can't damage your engine with insufficient oil volume because the high pressure oil system will cause it to shutdown before damage can occur. While it isn't common, I assure you that you can cause engine damage before the engine shuts down.
As stated in the other thread, the oil not having been changed in 5 years is a big problem - even if it wasn't driven much. From your description, you weren't leaking oil to the ground so it was either all going into the coolant, or you were burning oil, or both. Any/all of these situations can possibly cause serious engine damage.
If you are still seeing "red hot" coolant temperatures, then swap the coolant and oil temperature sensors and see if the coolant is still hot. Also, make sure you have the proper coolant volume in the system.