I think there are several things you're dealing with...
There are user created playlists, and there are "play"lists created / modified by MC.
A "playlist" is just a list of file references (or URLs, or other, but I'll ignore those for now). A playlist may reference the exact same physical file one or more times. How do multiple references get into a playlist? A user adds them to the playlist.
The "strange duplications of particular albums" issues seems to be suggesting that you have inadvertently imported the same file set one or more times, where each time the file resided at a different file path then existing MC entries. So if you move a file out from under MC, and then reimport this file from somewhere else, MC can have two entries for what you consider the same file. But they were not the same file, because a file is defined by its file path location, not its contents.
You're also indicating that MC's auto-import doesn't appear to be adding files to Recently Imported. This may be due to an issue some have reported.
MC's Auto Import can do a few things for you, for files under watched (auto-import) folders:
- It can Fix broken links (i.e. the file pointed to by the Filename field). MC will try to re-connect a moved/renamed file if it can, or when it can't, it can remove the file reference from the database (Library).
- When you delete an entry from MC, it can (when Ignore files previously removed from library is enabled) move those references into a special Removed database. This is how MC remembers you've deleted a file. And MC will move this file from the Removed database back in your Main database if you ask MC to re-import it. Or if you removed the entry from the Removed database manually, MC will import this file as if it were new.
I wouldn't rely on the Recently Imported playlist, since MC pretty much owns this. Instead, create your own Smartlist that shows you the last N days (or weeks or whatever) of imported files, from most to least recent.
Also, I have posted in the beta forum a view to look at your recently imported files. I'll post it if it is useful.
See also:
http://wiki.jriver.com/index.php/Import