I have read about your problems with PSO2, so I thought i'll kick in and maybe shed some light. Back in the days, PSO2 had a wierd quirk with it's files and it's very own updater.
When you were using the JP updater (Tweak didn't exist), the updater tried to set NTFS read access rights to a non-existent local account and effectively locked everyone else out. This could be fixed by manually restoring ALL access rights and then bypass the launcher, just to get it running.
However, PSO2NA is stored away in a folder, you don't have direct access into it, but you have "some" access rights to the folder of PSO2. What now happens is, PSO2NA completely obliterates Windows 10's "Store" model by just removing any access to it, locking everyone out - even the account used by the Windows Store. That's why you can't uninstall it - except if you could use SYSTEM (basically root, if you are familiar with Linux). Although the files are physically there, they don't get recognized as such anymore at all, even by itself. That's the reason it becomes unplayable after the first run.
Sure, you can manually restore all the access rights but then comes Windows 10's self-protection, which locks you out a second time and as no special constructed rights are set, they all get owned to the Store, but not you. It gets even worse, when the pso2launcher tries to access a path you don't have read AND write access to it.
To add insult to injury, because of this very reason PSO2 is NOT compatible with the Windows 10 Store. The game was made to reside in a static folder with full write permissions (f.e C:\PSO2 ), not in a variable one, where it can reign over it's own files.
Here is another question. The game seems to install to "100B7A24.oxyna_22.214.171.124_x64__wyfsmff9ynw7j" Do you see the 126.96.36.199 part? What would happen, if that changes to 188.8.131.52? Will it redownload another 80GB? Maybe.
So, here is what could work. PSO2 is marked as mutable, so there should be a PSO2-related folder in "C:\Program Files\ModifiableWindowsApps" and that path is supposed to be writable, update and start PSO2 from there, not the "C:\programfiles\WindowsApps" one. Problem is PSO2 killing it's own NTFS access rights after that, so we are back at square one.
But shhh, this is a problem, which persists up to this day even in PSO2JP.
Last Minute edit: A way to fix this once and for all was to install it on a FAT32 drive - there are no NTFS rights which can be messed up. But, Microsoft doesn't allow FAT32 on drives bigger then 32GB and thanks to the Store, you guessed it.
Maybe installing it to an external drive, formatted with ExFAT would work?