Nothing wrong with being an religion of violent crusades against unbelievers. If you've gotten to a point where you can systematically pull that off that's great. If anything more religions should try and go for something like that, instead of being content at leaving others alone.
Touché
If you look at actual history, Medieval Europe defined itself, and saw itself, as unified by its Christianity (Christendom). It's perfectly feasible for a religion to try and be domineering and use it's religion as a reason for military crusades. It is an interesting roleplay point. I admit it would be boring if SA conquered the whole of Dwilight which is why I think the other, non SA dominated realms, need to be a little more aggressive.
