FWIW, I agree with your suggestion.
There are undoubtedly many advantages in having a custom-written platform for the fan project wiki but the trouble is it needs to be supported. Unfortunately due to the pressures of "real" work and developing the forum software, Jay has not been able to carry out any significant improvements to the wiki since it was launched. (It still hasn't been skinned to match the rest of ot.com because some modifications were required to the HTML code).
I envisage that an off-the-shelf platform would be flexible enough to contain the fan project wiki, although some of the benefits of custom built software will be lost (e.g. the potential for closer integration with the forum, single user accounts).
There are open source ColdFusion-based wiki platforms available (e.g.) but they don't look very good (there's one here). The short-lived DVDHolocron site used the MediWiki software, the same as Wikipedia and Wookiepedia, and during the short time it was active it had much more participation than fanedits.com. However, it's a PHP solution and I don't know if Jay would want to go down that route.
Guidelines for post content and general behaviour: read announcement here
Max. allowable image sizes in signatures: reminder here