could someone point me to a place where the use of title packs is more or less explained properly?
Hylis explains the use of Title packs in this post:
http://blog.maniaplanet.com/blog/2012/0 ... -planet-2/
Joust, Elite, and Heroes are somewhat limited in their use of the title packs. They only have the custom gamemode, editor, and the seperate multiplayer ladder.
TM2 Platform has those things, as well as its own Solo Campaign.
Future title packs can also have texture mods, custom objects, and other stuff. Read more about it in the blog post linked above.
Above all, I think it was necessary to have some title packs during the Alpha/Beta in order to test their use and fix any bugs related to install/uninstall of them, and their use for dedicated servers, etc.