Hi, after reading everything and 5 resets i have to say that the trick is -Not to connect to the wifi or google account after reset. That way the reset works, otherwise it doesn't
Just keep persisting with factory installs. I did as per user Mantsam, except I connected to wifi, then used chrome to install aptoide straight from internet, it suddenly worked on like the 8th factory reset and now I can install APKs without Google Drive. I regained control of my phone then disabled almost every google and google sync, and basically if it had google in the name app so they can't interfere with my life anymore.
To anyone else having problems you could also try what it states here
If you did so, there are some workaround :
At the phone first set-up (you may need to factory-reset to get that) - When Motorola assistant asks for data safety (just before the Google accounts question comes up), don't click accept, but tap on "data safety guidelines" and tick both settings to off. Then accept."
I was about to try this next but it finally worked. Lets hope the error does not come back eek
Fear not! You can the following (network access is NOT required):
Open Google Drive
Select Upload
Select any application to navigate(i use Astro)
Select your .apk
Now its shown at your Google Drive even though you haven't upload it
Run it from there, it will install
Remember to remove it afterwars if you do not want to upload it when you will connect to the network
Try downloading via different browser, when I tried via Google chrome it failed when trying to install giving parsing error, yet if I did the same download via Firefox it installed no problem. HTH