This is a great write up!
To add to this, Pandaria can potentially be the ‘solution’ to a lot of the problems going on (or supposedly going on) for the Horde and Alliance. With Westfall still heavily damaged by the Cataclysm, and the Horde having suffered under a few Famines in recent history a large agriculturally rich land as Pandaria should be able to make huge economic impact on the world, simply if they can organize themselves and figure out how to sell their many products to the larger world.
Jade, Windwool Silk, Crops, Kaffa, and their other unique resources (like bamboo) should all command high prices in other regions, and be highly sought after. While having an Emperor may be one option, another is that Pandaria unifies under some sort of Mercantile state that is fairly free form in laws / regulations, but helps to negotiate trade with the other powers and protect its own territory. Pandaria could become a very economically powerful nation indeed with the right investments, exports, and treaties with the other factions, especially the Horde.
Not to mention, they should unify for exactly the reasons expressed above. With the Forest Hozen still a member of the Horde (appearing as armed members as of BFA), and the Pearlfin Jinyu potentially being members of, or extremely friendly to the Alliance (I don’t recall any Pearlfin Jinyu serving in the Alliance since Pandaria) the two superpowers already have footholds in the Pandaren continent. Combine that with the East/Westwind Rest, and their Karasang Jungle bases and both factions have substantial claims to Pandaria already. With the Zandalari joining as well, the Isle of Giants to the North may well still serve as a breeding ground for the Dinospeakers of Zandalar, and with threats to the West, Pandaria could well find itself surrounded on their own continent by foreign interests.
In that sense, forming a nation may be the best way to let them start influencing their own continent in a unified manner that they never could on their own, and establish the strong economic base needed to build them up.
To be honest, I’d really like to see Pandaria become sort of a ‘third-power’ on the World stage, while perhaps lacking the military, land, and Technology of the Horde and Alliance, it would bring to bear a rich economy, and resource rich lands, and a powerful enough defense force to let them maintain their hegemony.
Sadly, that would require some effort being put into the World Building beyond “Oooh look at the Shiny new Threat!”