@sethzbn It sounds like you have a few different issues here. The first one, confirmed by your dxdiag (and thanks for providing it), is this:
https://answers.ea.com/t5/Technical-Issues-PC/Sims-3-won-t-open-Alder-Lake-Intel-12th-gen-CPU/td-p/11057820
That's why the game won't open, and you'll need one of the workarounds in the accepted solution in order to be able to play or install content through the launcher. For now, please just use the Task Manager method every time. It's the most inconvient intervention but also the most reliable, and using it avoids any potentially complicating factors. If you'd like to try the Alder Lake patch, please wait until we've solved the other issues.
The launcher login doesn't always work, for various reasons, one of which is having special characters in your password. But you don't need to login to the launcher to install Store content; you should be able to do so through the Store website. If you can't, try using Firefox rather than Chrome or Edge, or disabling your VPN temporarily.
I can't be totally sure about the notifications, but it sounds like OneDrive is trying to sync your user data, i.e. the content in Documents > Electronic Arts > The Sims 3. OneDrive is going to be a problem unless you get rid of it or stop it from syncing the user folder, but if you want a quick test, pause syncing. Right-click the cloud icon in the lower-right corner of the screen to see the option.
Longer-term, you can choose one of the options here:
https://answers.ea.com/t5/Technical-Issues-PC/CURRENT-ISSUE-Sims-4-saves-user-content-disappearing-PC/td-p/12475370
The guide was written with Sims 4 in mind, but the OneDrive settings are the same. Whether you'd prefer to exempt the Sims 3 folder or all of Documents, or you want OneDrive gone entirely, is your choice; the point is to have no syncing of the Sims 3 user data. Let me know if you need more detailed help than the guide provides.
