I've done some research on this. It seems that WOW wiki was originally hosted by themselves and later moved to Wikia. They got their separate domain name wowwiki.com (but also wow.wikia.com as a "formal" wikia name). The layout they got is actually an "official" modified version of the default oasis theme by Wikia. I'm pretty sure that they're not a paid user as they got pretty high traffic. The requirement for a paid hosting is 20k PV per month. They are surely getting far over this number per day! If it's an exception case for WoWWiki, I do think we should be able to apply that modification too.
We're not make a traditional Wiki site and it's more or less like a first-hand, most up-to-date game guide. The reason we're expanding the width of our pages is the true need of showing the growing fertile information about the PAD game. The 670px width is no longer enough to show the upcoming new contents as the skill and names of the monsters are being more complicated. And I'm starting to work on some new high quality page layout with the extended width too. There're lots of other copycat PAD "wikis" outside. It's a competition for us to maintain our leading place in the game. I believe our design, and those upcoming stunning pages and customized layout will attract and retain more visitors. As a Wikia Councilor, i know the dev is working on "something" for a wider and flexible layout. But for the time being before the official release, I hope we can adopt to the current temporary solution.
For IT issues, we're trying to work to make the mobile version as useful as the Full Site one. However, we also faced a challenging problem: the mobile version doesn't support CSS and JS (at least in the traditional way). We still discussing about ways to resolve this problem among the admin team. If you got some idea how to work with the layout issues in mobileskin, we'll be pleasured to be advised.