From the point of view that the Wiki is a reference work for an original work, we *shouldn't* be fixing typos. The professional standard is to leave typos be and put '[sic]' after the typo. And that could be templatified to create a page that lists all the typos.
Really, I think of the Wiki more from the point of view of what is useful to a user. I don't think that most users really care so much about the
exact wording in the game, and care a lot more about what it's supposed to say when it comes to typos and such. Keep in mind that we're not a formal reference. I want the information to be accurate, but not to the point of distraction, and seeing [sic] after an in-game typo would be distracting to me. Not "ZOMG I can't read this!" distracting, but I just like it better when errors like that are silently corrected because I
really don't care about misspellings.
Having said that, I wouldn't mind having some kind of template that would allow me to, for example, use something like this:
{{bug|message=Malaise's name is misspelled as "Maliase" in the mission description for
whoever's
whatever mission.|display=no}}
If the display=no parameter is specified, then this wouldn't show anything on the page; maybe it's enclosed in <span style="display:none;"></span> tags or something, but it
would show up in the bug category page that devs or anyone else could use to reference if they want a really nitty-gritty list of every mistake that we know of in the game.