In many parts of the system, you get a warning message if you want to delete something. It would be nice to have this included for the import sources in an import slot as well. If you have a look and click on the dust bin icon, the import source is deleted immediately:
This makes that it sometimes happens that you remove an import source by accident and then you have to enter all import source information again. Especially in the case of an sftp import, this means that you have to gather all necessary information again.