If you edit your project and save it a bak file will be created again.
You can delete bak files and nothing goes wrong. Calm down, musikbear. Sure, they're there as a safeguard, but they occupy space, or if you don't want the project what's the point of a backup?
You can disable bak-file saving behaviour in settings ("Create backup file" setting, NOT "Autosave," autosave is different). However, as musikbear has implied, this can actually be problematic- it is best to have a bak file in case something goes wrong. I would not recommend disabling backup OR autosave behaviour. It makes more sense to delete unnecessary intermediate backup files later, IF NEEDED.
But I sometimes make incremental versions of songs, like Joy1, Joy2, Joy3, etc. It doesn't make sense to have a backup file of each of them, especially if I want to delete some of the original project files, or if they're large.
If you delete a bak file before completing your project 100%, nothing will happen. I can confirm: I have never completed a project 100%, I have deleted bak files, nothing's exploded in my face (yet). Avoid deleting backup files unless you have a genuinely good reason, but there's no sensible reason to keep around bak files of incremental versions of ancient projects.
