No need for any rigidness nor deadlines nor anything else but organizational structure. Without organization I don't really see a successful path ahead. Most of the "groups" I listed will be mostly dormant at first anyway and perhaps activate only if there's enough people to warrant it. Having a structure in place should that happen is not going to hurt. Project leads are probably not needed unless somehow this attracts dozens of people.

Edit: and I think you are misusing the word metaphysic,..
Quite possibly since English is my third language. The point is that there should be some ideas developed to answer questions such as: 1) have the people of the world evolved there, created by deities, migrated from an other world etc, 2) what if any realms of existence are known to the cultures of the world beyond of our Earth 3) what are the belief systems based on; bent physics, actions of supernatural/immortal beings manipulating the world or are they only extensions of imagination. There's more, but I hope this clarifies it a bit.

Could you develop here or in the other thread, your views about licensing ?
When the project has started and maps and other images have been created and attached to it, it's already too late to think how and to what end the outcome of the project and it's individual components can be used.

There's always the possibility that the project evolves into something worthwhile - something that has an actual potential to attract people outside the enthusiasts who created and worked on it in the first place. This should be thought of beforehand and whatever the net result is, it MUST be communicated to whoever participates - it benefits everyone to know what are the project goals and what - if any - restrictions every participant should adhere to when they participate.

Personally I'm not really interested in just fooling around for laughs but aim on being part of developing an actually usable world on which to base stories, adventures and gaming sessions. Part of that aim is to acknowledge the possibility that at one point we might have a wider audience. Again, personally, I don't really see a problem in having a commercial aspect (ie. actual publications based on CWBP or expanding it) although I understand it to be a very remote possibility.