Isolist realms often die a swift death because they do nothing and thus grow boring to the characters there who then move away. I would not propose to not interfere with 'mainland' matters, in stead I would actively interfere. Making a bunch of 'friends' in the south won't create any additional value unless they end up fighting each other, for in the end you simply split up your nobility, but add no true opportunities as you'll still have no wars and dynamics etc.
In stead I'd suggest to continue with the faith, leave regions like Irombro rogue, but maybe add one colony between Obia'Syela and the Shattered Valed and in turns you can choose to raid AA etc, you can move in to attack Nothoi, or simply protect your allies.
Due to it's position I don't see Obia'Syela being a standard realm in terms of what you can do with war, but the reason it's so unique is because of the culture and the RP. Focus more on that, keep the realm alive, adding 3 micro realms in the south won't help that much I think, especially not if they're friends.
