Front-end managers IS NOT a feature. That's only 3 pre-maid search types. And yes they are only available in install.sql. Feel free to create them on existing sites if needed.
Drag-and-drop IS a feature, and it's available for all websites (update or install)... but in order to know how it's working you can install a fresh SEBLOD on another website as an example, and replicate on your existing website if needed.
thanks a lot for your help and sorry for my late response. It seems to work fine, but what does the Drag-And-Drop really do (beside dragging and dropping :D) ? I guess it is not changing the Joomla Ordering, right?