This is little information to go on, a lot depends on codec and the type of footage you use.
Performance is very buggy. Projects freeze up and crash
It helps to reset your preferences (SHIFT + ALT while launching the app) and completely delete the dreaded cache folder in your user library. Always try those first. And try to create a completely new project and re-import the old one completely, do this especially if you updated your projects from an older version.
folders get deleted from the project,
This is a bit vague, you mean bins are deleted?
little things like title safe windows are broke
This is a bug, I can replicate it. You’ll have to wait out for a bug fix.
workspaces won’t save properly
Make sure to disable the ‘import workspace from project’ option under the workspaces menu. If not you’ll always carry the workspace of the person who last saved the project. Maybe try deleting your old saved space and re-save it.
external video via Blackmagic card is broke, etc…
Make sure to install the latest ‘Desktop Video’ drivers from the download page of Blackmagic. PPro needs the drivers to send a signal through a blackmagic card (Resolve may have these built in?). And remember you can’t just send any timeline through every card / mini monitor. Some support 4K, some don’t. Sometimes the same footage placed in a 1080 timeline sends the signal when a 4K timeline doesn’t (again, Resolve maybe scales this automatically since it is designed by blackmagic?)
Good luck! It sucks to have stuff go wrong like this! 😡