How to turn off trash?

You can use Shift+Delete instead of Delete to delete file(s) forever, but don't forget; If you delete the file forever, you can't easily get it back.

You can add a delete action as described at How to delete files bypassing trash . Files deleted from the console are immediately removed, but please note that under some circumstances they can still be recovered, if you want to securely delete files use the "wipe" command.

Hmmm.

Places->Home Folder->Edit->Preferences->Behavior->Include a Delete command [...]

Yes, console deletes have no "recycle" action - they are gone.