sounds interesting, but it would be cool to have a reputation system governed by other members that everyone CAN see as well... but I can also see how that would make a "popularity" problem happen
Hope it works out well, I know on most of the other boards I've been on that have a reputation system, it is generally visible, but it works out for the best. :)
I honestly do not belive the thread should be automatically locked if it's voted down. Rather, the admin/mod could take a look into it and /then/ lock it.
And what about ganging up? Ehhhh.....
As long as the mods would personally look at a situation that's been severely thumbs downed, I think we'd be all right. :P