Do PlayFile and AddFile still exist in the iTunes COM interface?

Question

I'm playing around with the iTunes COM SDK on Windows. I'd like to come up with a script that causes iTunes to play a video file, and either the PlayFile (associated with the liTunes interface) or AddFile (IITUserPlaylist) methods ought to do the trick -- at least in theory.
Unfortunately, neither of them work. They're both still apparently valid method calls, since my Java -> COM bridge barfs when I feed it invalid method names. But neither of them actually does anything. By way of contrast, OpenURL and AddURL both work perfectly -- and they'd be viable workarounds, save that they both assume the input file is streaming audio and store it in the library as such.
Have these methods been deprecated? If so, what have they been replaced with? Or is it more likely that I'm running afoul of one gotcha or another?
Right now, the only workaround I can think of is to write code that edits "iTunes Music Library.xml" directly, and I'd rather avoid that for what should be bloody obvious reasons.
Thanks in advance for any insight anyone has to offer on this.

Answer 1

In general:
- The best way to check if files are in a library is to drag the whole media folder to the library.  If something was missed it will be added.  If it is in the library is won't be added a second time.
- If you have a second copy of a file and iTunes does not currently list that specific file in its database then even if it is identical to one already in the database it will add it a second time.  So if you have file xyz on the internal drive and the external drive and add them to iTunes you will end up with two entries for the same thing in iTunes because you really do have to copies of the files.  While this can happen with two copies on a single drive, it will almost definitely be the case when you have a copy of a file on two drives because iTunes really sees them as two different things.
-Unless you know how iTunes works, avoid moving files yourself.  Let the consolidate feature do all the file moving.  Manually moving files can really mess up iTunes unless you know what you are doing and have iTunes set to not try to do it itself.
- There's no clean and easy way to delete duplicates.  The best thing is to change practice so you don't create them.   Here are  references:
How to find and remove duplicate items in your iTunes library - http://support.apple.com/kb/HT2905
http://dougscripts.com/itunes/itinfo/dupin.php (commercial)
Posts by turingtest2 about different types of duplicates and techniques- https://discussions.apple.com/thread/3555601 and https://discussions.apple.com/message/16042406 (Note: The DeDuper script is for Windows)
http://www.hardcoded.net/dupeguru_me/