Why don't we scale back the idea here? In a way, what's proposed here is not one thing but actually two things IMHO. Before you can even make this treaty a reality, you would need the multi-organizational framework to make this happen.
In other words, we would need to form a U.N. of some sort (hopefully one that functions better than the one in reality) and then this treaty is merely an example of a "resolution" that this "U.N." can potentially discuss/draft.
It's quite apparent that the second part is not happening any time soon for a multitude of reasons/concerns many have already expressed earlier.
However, what about the first part? Once such a framework is set up, should any big pressing issues (whether it be a giant griefing organization, infinite bounties becoming an issue, etc.) can be dealt with quicker because the infrastructure for the various chartered companies to meet and the decorum and discussion format is already in place (or at least partially in place). Without it, time would be wasted to get this infrastructure up at the last minute when the need suddenly arises.
This can also be a great feedback tool for GW. Let's take Bluddwolf's issue/proposed idea with dealing with infinite bounties. Should a majority of CCs agree to not use infinite bounties or at least vote that they want it removed. This is a strong signal to GW that the mechanic at the very least warrants a second look. (Heck if we want to up the RP on this, convince the GW to maintain/administer the hex that holds the U.N. to ensure neutrality. I've never played EVE but from what I've read CCP has an in-game presence so I guess this might be somewhat similar?)
Now, many ppl do not like the U.N. Common reasons being it never really has the power to enforce it's mandates (but given how it seems no one wants to be in any binding agreement anyway, this is probably not an issue) and that the few make the decisions for the many. In other words the security council is an issue and the fact that there are 5 veto wielding permanent council members. This can be solved by making the general assembly = the security council = etc. In other words every CC has an equal vote. Doesn't matter whether you're TEO or a CC with 6 members, you still have 1 vote. This would therefore give small CCs a lot more voice then they would have otherwise.