I didn't vote on this one because I agree with Voronwe (which I usually do except on the Nazgul-over-Osgiliath scene ).
As for wanting to hash out the Constitution before opening the board...
I am what they call a programmer/analyst. That means that someone comes to me and says, "Hey, can we get the computer to ..." Then I spend days squeezing information out of them so that we can decide how things should work and look, and come up with a document called user specs. (Hang in there, the point is just ahead.)
The point: it doesn't work that way. Inevitably, the user specs, no matter how well thought through, are no more than a starting point. In reality the process is iterative, as we refine what we know about the problem and come up with the solution that in turn triggers new questions.
Same thing is going to happen here. We (you, I guess, since I am too new to participate ) can spend years on every tiny detail. Once the board is open you will inevitably find that there are hundreds of scenarios that have not been foreseen, and the rules will need to be created on the fly. Even the US Constitution had to be amended many times.
If I were here long enough to contribute, I would suggest that the board be open as soon as practical, but the number of new members be limited to X per week, first come first serve. X would be whatever the admins can comfortably process, and as soon as practical would be when the very basic guidelines are in place but details are still being worked out.
What I think will happen in reality is that a few people will rush over because their friends are here and they want to participate. These people will be good citizens and can be absorbed with minimum trouble, especially since their friends who want them here will be eager to help them adjust. It's possible that a few other people will come and make trouble on purpose, although personally I doubt it. If they do, they will be dealt with firmly and politely by the membership, and if necessary by the admins.
It will be months if not years before anybody who is not an avid TORCer would want to join this messageboard out of the blue and by that time we will have all the experience of assimilating newcomers we need to come up with realistic and sensible guidelines.