Hi gostwyck,
I just got my 500D not too long ago. Generally it is ok for the price range and have been using to take stock images since, replacing my point and shoot camera. I am also using the kit lens currently and it gives reasonably sharp images. 

The idea of forming a Co-Op for Micro stock photographers appears to be interesting. But from the operation point of view I think it is not so easy. Most Co-op are not very successful.

Co-op are not open to public. It caters for its own members only and and profits that the Co-op gain is distributed to members as dividend. Hence if you want to be part of the Co-op, you need to buy shares in the Co-op. It is therefore not free in the first place. It is just another form of company.

Management of Co-op is under the control of committee members elected from the members and the election of committee members may be carried out annually or at any suitable time period subject to the conditions stated in its Constitutions.

Therefore from what I see, Co-op can only be formed within a country but to open up world wide may not be possible.