Disclaimer: Obviously not going to work for all problems, especially if your issue is related to Firewall/Antivirus or anything outside of the Bnet application itself.
TL;DR - Battle.net App will not connect properly even if you give it administrator privileges. You need to actually give Agent.exe administrator privileges before any game will actually update or install.
Alrighty, so now for the long version. Spent 14-16 hours trying to debug this out of pure frustration. Updated Drivers, Rolled Back Drivers, went and made sure there wasn’t any issues with my firewall and antivirus, completely uninstalled the Bnet app and all residual files, and of course I gave the Bnet application itself administrator privileges. Could not get it past the initialization part of the installation process, didn’t pop an error, just… Nothing…
So, basically the reason for the bug report is because when you give the Bnet app itself administrator privileges, it does not actually give Agent.exe privileges. No amount of installing or uninstalling would’ve changed it. So, going into \ProgramData\Battle.net\Agent\ and actually giving Agent.exe administration privileges is what was required.
Would be exceptionally nice if giving the Bnet app privileges itself would also in turn give the update agent privileges. Or, at the very least have some information posted somewhere with this solution for people in my predicament. Spent a ton of time browsing forums and the help area without any information about Agent.exe specifically needing administrator privileges.
Anyway, spent most of my free game time on getting the thing to install. Now, I am off to work. Hope everyone has a good day, and all of your installations go incredibly smooth!