Is it possible to temporarily turn off the site or disable it?

Hmm. I run some vbulletin boards which have that feature and come to think of it that'd be really convenient.

For now I wrote into the guild rules that my members aren't allowed to bitch about the site design or I'd reset it to the default. Hehe.

I'm afraid there isn't a way to disable your site, but you COULD change the URL for it and then it would just redirect to the dkpsystem.com page (though that would make it look like it was disabled).

Might I ask why you wish to have the site disabled?