(Note: This is long and boring. Sorry...)
I was actually coming up with some ideas myself. Instead of something ridiculously long, I was thinking we could call the organisation something like the Inter-Regional Assembly.
The first thing that came to mind is how to organise the structure. What we could do is have a chairman who organises and runs sessions as well as picks a topic to debate about. The deputy chairman helps the chairman organise sessions and fills in when absent. The assembly members take a few days to a week (this is taking into account that we are not always online) to discuss what kind of actions need to be taken and vote.
I also believe that the IRA should stick solely to role play matters, such as what to do with war criminals from the recent conflict with Malvad or proper/more organised trade routes since this already resembles the Regional Assembly.
Also, every month a new chairman will be elected. The person with the most votes becomes the chairman and the person with the second most votes becomes the deputy chairman. New assembly members are admitted in by the current members.
Also, just for the sake of it, the IRA should have a stronger military presence. This is almost like a "League of Nations/United Nations" scenario.