It takes a lot of time to import a deck, especially the media files. And if you delete the deck, you’d also need to run a check media and then delete all the files before syncing.
There are usually lots of options for shared decks, so I go through more than a few of them when I need to. This means I also need to wait until the importing finishes completely (which can be slow at times) and I need to delete all the files later.
Suggestion
I think a “Import Media” toggle option would solve this as a lot of decks work without the media files (the media files are not the main content).
Might importing into a separate Profile achieve some of your goals? You could then experiment with the deck before deciding whether to import to your main Profile.
Importing a shared deck not only creates Notes and Media, but also can create Note Types. I agree that deleting all of these is a bit of a hassle.
I think it just doubles the effort. And now you also got to import things to the main profile. And the times for importing won’t go down. It might be a good thing for the clutter, but I believe we’ll agree that we still waste time by importing the media files.