Definitive Word On ID3 Tags, Library Files & Which Data Is Stored Where...

Question

I have spent a few hours just now (and have read the discussions a lot previously) on various iTunes issues, namely ones pertaining to organization and storage of data & info. I still have quite a few questions I would like the definitive answers for. If anyone knows for sure, thanks in advance for your response!
1) Is there any difference between how and where iTunes stores data for audio (mp3, m4a, aif, etc.) files vs. movie (mpg, mp4, mov) files, and if so, what are they?
2) In the info tabs/panes of tracks in iTunes, is the entered data stored in separate places? i.e., the info under the INFO pane stored in the individual media file itself while that in the OPTIONS pane stored in the main library file? Also, did I read correctly that Convert ID3 Tags causes more of the library file data to be embedded in the media file itself? (Not desirable of course, because each play would in effect "modify" the file as if it had changed and needed to be resynched, since play count is part of the data).
3) Is there a difference between where editable data (artist, title, equalizer setting, genre, rating, etc.) is stored vs uneditable data such as play count, date added, last played, etc.?
4) Is there a list somewhere online that shows what data is stored in the library file (settings unique to the iTunes) and what is universally in the standard ID3 tag in the media file itself?
5) Is it safe to assume that rating, equalizer, volume, remember position and start/stop time settings for each individual track are not in the ID3 tag but only in the library file? If so, one can then assume that merely copying the library file will preserve these settings?
6) Are ID3 tags applied and applicable to movie and audio files similarly, and do they further differ how & if they are used among each file type (mp3, m4a, aif, wav, mpg, mp4, mov, etc.)? I know with movies you cannot set or change the poster frame in mpg (muxed) files, for example.
7) I do all my iTunes importing, editing, managment, etc. on my PowerMac desktop, with the prefs, library and xml files stored in my home folder on the PowerMac's OS drive and the large media files store on an attached ext. 500 GB FW drive. If I use a synching program to continuously keep the library/xml files the same on my iBook laptop's home folder and the media files the same on another ext. 160 GB FW drive, then when I use the iBook with the 160 GB at different events it should operate exactly the same a when using my PowerMac at home with the 500 GB? The only thing I should have to change is the location of the iTunes folder in the Prefs on the iBook to point to the 160 GB, right?
8) Finally, now that iTunes 7 allows you to indicate sort order ("The Beatles" can now appear under "B" without writing "Beatles, The" as I have been) would it retain that sort when importing the song list into other database programs or even an iPod, or would it default back to "T"? (AppleWorks database has a similar feature where you can specify an ARTIST field which sorts by first letter of last word, but won't stay that way in other programs).
PHEW! ...long post I know, but I spent a lot of time reading and hopefully over time I can get the answers to most (or even all) of these questions. Thanks!!!
PowerMac G4/500 MHz (1 GB); iBook G4/1.33 GHz (1.5 GB)   Mac OS X (10.4.9)   (still using 10.3.9 Panther on PowerMac)

Answer 1

I read this on the ID3 site:
ID3 tags were designed with the MP3 file format in mind. ID3v2 tags will break formats which are container-based such as Ogg Vorbis and WMA. Here is some information on specific formats:
ID3 tags work in MP3 and MP3pro files
WAV has no tags
WMA has its own tagging format, which is specified in the wma spec, available in the MSDN (which unfortunately, basically does not allow Open Source implementations)
Ogg Vorbis uses "Xiph Comments" (same as later versions of FLAC and Speex), which are embedded into the Ogg container. You can find information on these in the comment and container specs on www.xiph.org
AAC uses yet another tagging format, which does not at present have a published spec as of 3/1/2006.
So since I rip in AAC, does that mean the tags work differently, are stored differently or offer different editable info? Also, I found nothing regarding tags for video files as I mentioned in my question. Within iTunes I am assuming all the information you may edit or view when you Get Info for each file is not all stored together: some is in the file's ID3 tag and others in the iTunes Library file. I guess you are always safe if you keep back-ups of your media files and library files, even if you don't always know which info resides where.
I found a complete list of frames (fields) that are available in ID3v2 at the following link, many not available in iTunes, but the site lists other apps that allow you to edit tags for both Mac & Windows.
http://www.id3.org/Frames
I am curious, if you use another app to edit the tag with a frame not offered in iTunes, will it still work in iTunes (like if you use the frame for synchronized lyrics; since it is part of the tag itself will they show up when played in iTunes even though not editable in iTunes)?