FINALLY !!! NEW BUILD UP
I finally managed to put everything together, as best as I could and here we are.
The whole thing has been restructured, so a CLEAN INSTALATION is absolutely required. Don't take any risks if you don't want issues, and if you do, please don't post complaints in the thread.
The camera has been completely fixed. We basically went back to the old Lollipop days, where Camera v2.5 (or 2.7) was the last fully functional version. Anything newer than v2.x, won't let you record in 1080p. I removed zaclimon's hack, meant to bypass the resolution check, but that caused autofocus issues, so I had to give up on it.
I also took the liberty to add 3 apps from Nitrogen, Camera, Gallery and Clock. If you want a different camera, you can install one and you can just disable the one I included, from Settings/Apps. I thought it would be nice to have a preinstalled Gallery app so it can go hand in hand with the Camera app. You know, you snap a picture or record a video and now you have what to open them with). The Clock app is great. I really missed it and its "shake to dismiss alarm" feature which is great when you wake up in the morning and you can barely see what's on the screen.
As I previously mentioned, the new restructure broke the native screen recording, but using "Screen Recorder - Free No Ads" (by Kimcy929), from the PlayStore, will let you record your screen without an issue, and the app gives you a larger variety of options as well so this is not a problem in the end.
This was made possible with @spezi77 's and @nitin.chobhe 's assistance, so kudos to them for the help, support and their patience. They deserve our respect.
You can find the required files in the first post and the other modifications I made, mentioned in the changelog (2nd post). Read instructions carefully (for "CLEAN INSTALLING", of course).
After the phone boots up, you'll notice that the UX is a bit stuttery, but that's completely normal. Just give it a few minutes to settle. Also you might think that the first 2 cores stay at 1.5GHz all the time, but that happens only until the phone gets everything ready, so don't worry about that either. Everything will "stabilize" after a few minutes.
That's pretty much all.
Enjoy it !
Cheers !!!