Questions before downloading Wiki plugin

I'm very, very tempted to install the Wiki plugin. But despite reading through the plugin description and watching the video, I still have a few questions:

1 - What if I have an existing MediaWiki install? Is there a way to import that information to the new WordPress-Wiki site?

2 - What about MediaWiki extensions? I really only use them for protecting my site from vandalism, so if WordPress's extensions could do the job there, instead of me needing to rely on a massive IP Blacklist file, that'd be awesome!

3 - What about updating the MediaWiki software itself...does it need to be done separately from this plugin? Does that need to be done separately? (That's my least favorite part of MediaWiki.)

If anyone can help me answer these questions, that'd be awesome!