Question:  Do I have to agree to allow another broker to co-broker my listings before I can co-broker their listings?
   
Answer:  No.  You have both signed a "blanket" co-broker agreement that covers both sides of the co-brokering relationship.  If another broker allows you to co-broker their listings, you are not required to do the same.  In fact, you don't have to select any brokers or make any of your listings available for co-brokering in order for you to co-broker the listings to other brokers.  However, if everyone did that, there would be no listings available for anyone to co-broker.

Question:  Can I let a broker co-broker my listings but not have to co-broker their listings.
   
Answer:  Yes.  Of course you are never required to co-broker any listings.  And if you like, you can easily ignore listings or brokers you are not interested in working with.  For example, you can "flag" listings that you are "not interested" in as well as "hide" all listings from a specific broker.

Question:  I have several broker associates that I would like to co-broker with in our own "private" network.  Can this be done?

Answer:  Yes, easily.  All that needs to be done is that each broker in your private network simply designate each of the other brokers in your group that they will worth with.  Then, any listings submitted by any of the brokers in your "network" would be available to everyone in your closed group.