In reply to Senff.

Senff, for security reasons, we are told not to even keep inactive plugins on our live sites. Hence the need for the option to keep either data or settings for the future, in the case we wish to use that plugin again. Jeff himself was happy that his Gravity Forms forms were still in the database.

A final (and probably the most sensible) option would be to easily allow import and export of a plugin's settings and data (not custom for each plugin, but registered tables and settings with a standard routine which works across all plugins).