I just finished adding a utility that creates a tag database from a given tag (will walk its dependency graph). Well, it creates two rather. The first database lists the source tag and all of its references (and then the reference's references, then then theirs, etc etc), the second database lists each tag that had erroneous dependencies (either missing from the tag set, skipped by the database construction, or for some reason failed to load), along with what those dependencies were.
When you extract a tag, it will also create a database with all of the extracted tags.

Besides auto-generating tag archives of a specific tag, I had another idea for usage of these tag databases (which I can really beef up with extra info, but currently I'm only going off the same database format bungie uses). Just not sure if I really want to spend the time implementing the idea as its a type of coding I have never even touched on before :/...

It wouldn't be trivial to get this working for Halo 1 stuff either, since my code library includes everything I need to interface with them too, and the systems are designed to work without hardly any game dependent data. I know people would kill for some of the utilities I've got setup for Halo 2, to work with Halo 1. We'll see how things turn out