I'm sure there's cleverer ways of doing this - but best, simplest way I can work out to create a style guide is to have certain pages worked up as the models, and then to copy that formatting for all pages of that type. So, for each production, musical number, character, performer etc.... one highlighted page that's as close to perfect as we can get. There's some standard wiki formatting elements we need to consider whether or not we want to employ - such as whether to only use a wikilink once per article. For example, on Rumpleteazer's page, we don't need to link every time Mungojerrie is mentioned! But we also don't want readers to be searching for the links when they need them.
We also need to be practical - we've over 2000 performers in the database and the vast majority of them, we know nothing apart from their name and the role they played. Some we've got the information from the program at the time, so a biography from 1987 or whatever, maybe a headshot. Currently active performers we can find a lot more about than someone from the 80s. So, for the performers section of the site, we have to be flexible and accept most of the pages won't reach full detailed levels - but that doesn't mean we can't try to have something here that their relatives would be proud to see pop up on google!