I think the MSQ is following a "modern" take on FFIV. There are the obvious parallels, a shifting cast, characters lost to the plot coming back, Estinien in general, Ayermic shares a few traits with Cecil.
As far as the GoT thing, I don't think the parallels are in the dead cast, but in the sense that much of the plot focuses on Good Men or Leaders that genuinely care for their people/subordinates, and the myriad ways they get screwed over.
I think Nidhogg might end up serving as the Common Foe Ishgard and Dravania need to finally settle their differences. Whether the peaceful Dravanian faction decides Nidhogg needs to die, and whether they contribute to that cause remains to be seen.