Diesel Bombers - 02 high milage - engine suddenly seems quite

So I bought a 2002 F-250 - manual, 4x4, crew cab lariat - with 265,000 miles oof - never thought I'd be buying a used truck with so many miles, but I think I got a good price and am willing to do the work.

I have a new issue and some questions on possible related issues multiple

As recommended by some, I added some Archoil after changing the oil (full 16 oz dose)

I live in the mountains of NC - and i noticed on cold mornings, it took a while to warm up and would 'buck' as some folks here describe. After adding the Archoil - it seems to warm up faster. After 2,000 miles of Archoil - while on a long drive (5 hour drive on the way back from hot Savannah, GA) the truck suddenly seemed more quite - like the engine has less high end sound (high end as in 4,000 hertz on the audio spectrum and above) like turning the treble down on the radio - it appears to have lost power in the high rpm range which I think based on what some folks on this forum say it is losing boost - I checked turbo and spider connections and they seem to be okay - at least visually (should I spray soapy water on the connections?)

The guy who owned it before me included a tuner that also reads codes. The codes that came up were :

P0541- Manifold Intake Air Heater Circuit Low
P1108 - Dual Alternator BATT Lamp Circuit Error
P1105 - Dual Alternator Upper Fault
P1106 - Dual Alternator Lower Fault (Ctrl)

I used this as an opportunity to take the tune off the truck and return it to stock. After another drive I checked for codes again and got the same 4 - I am quite sure these codes are none to really worry all too much about at least from what I have read on this forum - some folks call them 'soft' codes (i could be wrong)

Another issue I am having that may or may not be related is starting - 1 in every 10 starts, the starter turns and then kind of whirrs - as if bendix is not engaged long enough - some folks say grounding, some say replace starter - some say replace starter with more powerful starter - open to other ideas - not sure if it's related to this power loss issue

So far, the only thing I have done other than Archoil, oil change, new tires, and changing tune back to stock is I replaced the CPS sensor - which I think has given it a subtle, more smooth idle and acceleration.

Next thing I plan to do is order a HPOP reseal kit.

Also, I have been using DeadHead Diesel as a resource - do y'all like his write-ups and advice?

Thank y'all - this forum has been a great resource already - I am trying to pin point this issue