That looks.... AWESOME!!
As you are correct, WoWDB does not break mailboxes into factions, which means I would have to copy and edit, saving one as the "original backup for updating". No big deal there.
I have Python 3.3.x 64 bit installed, but even after reading the page's instructions, I could not figure out how to install BeautifulSoup. Also, when I want to parse an update, do I run the batch file, or mailboxes.py? I am guessing the batch file, as its code looks like it creates the latter file.
As for floors, I noticed that Dalaran lists 1 and 2, Ogrimmar is 0 and 1, and the Shrine of Two Moons is 1 and 2 but Shrine of Seven Stars is 3 and 4. Is that a parse issue, or does the game return those values for those zones' floors? Just curious if I need to edit those, or if they are correct, yet odd.
Two last questions for now: how do/should I look at WorldMapArea.dbc, and if the game client does not save mailbox locations in its cache, what is this file used for?