I made a tool for generating the code for lyrics. It should be helpful. (It has very basic (like, very, very, basic) support for the Vocaloid Lyrics Wiki too. I can make it better if anyone plans on using it.)
I don't think that's a good idea if we want to stay consistent. Other UTAU's also have multiple voicebanks and we don't separate those either. The voicebanks are very different, sure, but they're still from the same character.