I reluctantly installed Galaxy a few months ago and it's been ok other than exiting a game screws up galaxy's resolution and I have to completely shut it down and restart it to use it again.

That, and your update today completely screwed my installation. I completely uninstalled and reinstalled, but it will sitll not work.

I never should've agreed to update

edit - after another unintall, reg cleaner, and restart I was able to install it. Rather than remembering my settings , it started and immediately began updating games without my consent and would not let me cancel the update. Even after unchecking the auto updates it continued to update no matter how many times I pressed cancel. This screwed up at least one installation of a game that I needed on the older version for the mods I'm using, hopefully I still have a backup of the version I was on. What a pain in the ass all because it can't save my settings locally after an uninstall or cloud save my settings.

And again, I never should've agreed to update galaxy to begin with. lesson learned

If you need to downgrade a game,
1. Click the "More" button to the right of the Play button, choose Manage Installation, then Configure.
2. Uncheck "Automatically update to newest version" then select a previous version and click the OK button.

You can also disable automatic updates for games:
1. Click the cog wheel in the top left and choose Settings.
2. Click Game Features on the left.
3. Uncheck "Auto-update games" then click the X button in the top right to close the window.

I can't comment on anything else, since I didn't run into those issues. But you're more likely to find people willing to help in the dedicated GOG Galaxy forum then here, in General Discussion.

Sounds like skill issue :p

Based on other forum posts, maybe you're referring to the Failed to load game database error. Anyone who came across the same issue can try exiting GOG Galaxy, then deleting either the whole storage folder or just the galaxy-2.0.db file. More details in the following threads:
• GOG GALAXY update: Proteus brings customization options, GOG wishlist and more - post 8
• The "Failed to load game database" error. - post 2