3. Even if you did have claim under Shadovar, no heir of Shadovar-contra-D'Hara exists. Find me a descendant of Shadovar's rulers who can press the claim, a direct descendant with some kind of real claim. Simply because you were bros with a realm doesn't mean you are the lagl inheritor of their rights and liabilities.
D'Hara does have family of an ex-Shadovar ruler. And he's not about to swear fealty to the Lurias any time soon. D'Hara is the sole successor to everything that once was and that would have been Shadovarian.
Luria Nova has in fact done several of those things. The Dragon King has been denounced, and Luria has declared its own monarch. Furthermore, why would anyone declare Paisly D'hara's de jure capital? Luria would recognize it as Port Nebel. Furthermore, Alanna Anaris has just as much, if not more claim on D'haran lands than the majority of the Nobility of D'hara. She conquered it, the Monarch of Shadovar passed without issue, and therefore, the conquering monarch would have claim by rights of inheritance. Luria may not exercise de facto control, but in the BM universe where the international law you cite has no relevance because it does not exist, it still exercises a de jure claim through right of conquest. Furthermore, if you look at the diplomatic dealings, that doesn't necessarily mean a nation gives up all claim on the lands the entity it is dealing with holds. North Korea and South Korea hold to an armistice, and both will tell you that the other half of Korea is rightfully theirs and both are to a degree, correct in this.
A lurian shadow government is an interesting idea...
Conquering monarchs? The son of a former dictator of Shadovar is D'Haran. He has a far greater claim than Alanna Anaris does.
Of course it doesn't. 
D'Haran internal politics are remarkably stable, while D'Haran external politics are not geared towards a colonialist agenda. Lurian internal politics are just a series of rebellions, secessions, unions, and usurpations, while their external politics, whenever they can manage one, is to bully and try to vassalize their neighbors.
And there has never been a single D'Haran secession, nor a single D'Haran lord switching to another realm, thus far. Starvation has shrunk our realm on multiple occasions, but we always sprung back up, and stuck together. The rebellions were few and long back. We have a history of being religiously open, not having any native religion in quite a while but rather a history of a religious people following foreign faiths, while the Lurias have a relatively old native faith and have not started adopting SA in a significant level until relatively recently. D'Hara lived as a trader's realm, open on the world, always making dealings with as many realms as possible, whereas the Lurias tend to be isolationist, and rarely bother with foreign realms save for the rare moments they are stable enough to bully their neighbors.
D'Hara and the Lurias may share similarities, but their cultures are definately distinct.
