While I appreciate your motivation, I do not agree with your solution. You are advocating forcing someone's standardized version of Islam onto everybody, albeit tailored to subgroups (larger than 5 million). Groups with fewer than 5 million adherents will simply be ... what? ignored? forced? excommunicated?
The only solution is to make people understand that violence is not the way to settle differences; better still to accept those differences and just live and let live, as long as basic human rights are respected. Even if someone believes that girls' education is wrong or burqas are compulsory, they are welcome to make their case and we can debate them with facts and logic. However, since many Muslim governments are themselves abusing differences within Islam to serve their political agendas, it's hard to see how the above idea can be implemented.
As for terrorism and pan-Islamism, those are much more complicated topics which can be debated on their own. For the record, I don't buy the accusation that Muslims suffer excessively from pan-Islamism. There is pan-Judaism, pan-Christianity and pan-Hinduism, and their adherents are just as passionate and active as any Muslims.