Switching over from apple/google password manager to keepassxc + syncthing + git + external backup. Questions

1. ⁠How do i backup version of database files

As advised by docs

``` We recommend using a storage service that keeps automatic backups (version history) of your database file in the event of corruption or accidental deletion.

```

Is git the right approach? Im familiar with git

2. How do i make the directory that stores the database files only editable/writeable from keeppassxc? I dont want to accidentally edit/delete files and it syncs with all my devices through syncthing. Basically i want only keeppassxc app to edit the files in directory

3. How to use key file? Is it worth it?

4. I use windows, linux, macos, iphone, android pretty much all OS and is it seamless?

Any other tips and tricks i should know about?