fallout-4,ps4 – Can a Saved Game Be Carried Over Between Editions in Fallout 4?

Yes you can, EU has 1 Playstation store (except for UK and Germany). So you can buy from there in any EU country (again except for Germany and UK).

Also you don't have to be worried about region locked games, only the stores are region locked. But if you have several accounts (1 for each store) you can just buy from that store and download it to your PS4 and play with any account.

According to this link from Sony, when you log out of PSN (manually logging out, or in functions like going to rest mode/shutting down) the PS4 checks for newly saved data, and attempts an upload. However, the page does not go into great detail on the timing of these uploads.

This GameFAQs link seems to be largely speculation. A user does mention that you can manually upload data files by doing the following:

Settings -> Application Saved Data Management -> Saved Data in System Storage -> Upload to Online Storage -> [Game or App] -> [File you want to upload] -> Upload.

It's an unfortunate annoyance that the manual process is so difficult, especially since you don't know when the game is going to crash. As of right now, there doesn't seem to be a way to increase the upload frequency.