I have GREAT news.
Fortunately both of our theories were wrong...
For the life of me, I cannot wrap my head around what exactly happened and when... but one thing is for sure, my memory definitely failed me because I must have cleared or reset the cmos/bios settings as it was definitely the culprit.
Turns out, Dufus was on track with the suggestion of disabling C State.
When my bios was defaulted... C state went to something like C6 with retention or something along those lines...
When that option is enabled, the boot issue happens.
Disabling C state altogether does fix it, however, enabling it, and changing the one setting of "C6 with retention" to "C0/C1" (as I originally had it, which I found through browsing through photos I had taken of old bios settings when I first set things up and built this PC) then it boots fine.
I put the Raid 1 array back in, and to my delight... IT WORKED.
Windows is back up and all raid arrays are fine.
Perhaps one day soon I will either build a NAS, or get a 5tb external drive to back up all of the data from this Raid 1 array, and then rebuild the Raid 1 array the way you mentioned rather than the lazy way.
For the Raid 0... I don't care if it fails as that is just a gaming drive.
But I'd be lying if my heart didn't skip a few beats at the thought that I may have lost the data on the 5tb array.
Well... with all that said... I'm confident that I'll be stubborn enough to attempt this modded bios again, keeping a keen eye on the C state settings in my darn bios