Problem with create modify work item - receiving error work item in read-only state

RTC Version 5.0.2

We have a project for our DRS and another project for our development work items ie:Capability, Epics, User Story, Action Items.

We work with external partners that cannot have permission to our development project but needed to have access to Action Items impacting them.  Since our external partners have permission to access our DR System, I enabled the Action Item work Item in the DR System project.  This made sense since all the users were in this project and are partners have permission to this project.  However I had to bring over the teams and categories from the development project for the Action Items work Item.  The only team we had in our DR System was called MDRRB.

I did not add users to the teams I brought over, I thought it would be sufficient to just have all the users in the MDRRB team.  However I found that an Action Item Work  item cannot be created or modified.  I was able to create a work item if I added that person to the team the Action Item was being filed Against. It also worked if I added the person who was modifying the work item to the team the AI workitem was filed against.  What doesn't make sense to me is if I would have to add every user to every one of those teams....the person modifying the Action Item or Creating the Action Item is not necessarily a member of the team the Action Item is being filed against.  I then associated all my categories with the MDRRB team (where all the users are) but I don't think that will work for plans. Also I did not know if that was the best thing to do is to associate multiple categories with one team. 

In summary I need a solution on how to be able to Create/Modify the Action Item work item.  Adding all users to each team seems redundant.  Is there another solution to my problem.