[Mediawiki-l] Ramifications of GNU license

[A R]

Hello all!

On my Special:Version page I notice this text: "MediaWiki is free software;
you can redistribute it and/or modify it under the terms of the GNU General
Public License as published by the Free Software Foundation; either version
2 of the License, or (at your option) any later version."

1) Does this mean that my wiki has to have the GNU free documenation license
on all of its pages?

2) Am I not allowed to make money with content on my site, in terms of
putting up google adsense advertisements?  (It feels like I can since I've
seen others make extensions to do this...)

3) Am I not allowed to make money with content on my site, in terms of
reprinting it on physical paper and selling copies, for example?  If I don't
have to use the GNU license, I could reasonably have a policy where all or
some content users submit becomes my property, right?

Thanks.