Regarding 2: I've had problems with this strategy. Even though I used the swap technique instead of overwriting, files easily get corrupted on common file systems, and if it's just the user force quitting the application during the operation. (I mostly use Ext4 for testing.) Whatever Sqlite does under the hood is way more resilient to such problems. I guess that's because the Sqlite developers have been testing ACID compliance extensively.
In one of my Racket applications with high integrity demands I've resorted to writing the temp file, swapping it with the original, then opening it read-only and verifying all of its contents. That is very reliable but obviously slow. But in another application written in Go I've switched entirely to Sqlite even for simple settings files and had no problems since.
In one of my Racket applications with high integrity demands I've resorted to writing the temp file, swapping it with the original, then opening it read-only and verifying all of its contents. That is very reliable but obviously slow. But in another application written in Go I've switched entirely to Sqlite even for simple settings files and had no problems since.