Takumi Vault - Backup & Restore Manager

By default, backups go to a directory with a random suffix one level above your WordPress installation. Before writing anything, Takumi Vault checks whether that directory is actually reachable over the web and refuses to use it if it is. You can set your own path in Takumi Vault > Settings, and it is checked the same way.

No. Takumi Vault is written entirely in PHP and the WordPress API. It does not call exec(), shell_exec() or any external command, so it behaves the same on shared hosting where those functions are disabled.

Yes. wp takumi-vault backup --type=all takes a backup, and wp takumi-vault restore <id> puts one back. There is also wp takumi-vault check, which reports what the host can and cannot do and exits non-zero if anything would stop a backup, so it can gate a deployment script. This is worth using where you can. The command line has no browser waiting on it, no execution time limit and no dependency on WP-Cron, which only fires when somebody visits the site. A quiet site with a real cron entry calling wp takumi-vault backup is the most reliable way to run this plugin.

Its settings, its own tables and any scheduled events are removed, along with the copy of the database that a restore kept so it could be undone. Your backups are not deleted. They live outside the plugin's own directory and are yours; removing a plugin should not destroy the thing you installed it to protect. Delete them yourself when you no longer want them.

Yes. File backups are zipped after the fact, and the maintenance window is kept to a minimum.