However I also think there's other ways of looking at it, If you conquer Skyrim and take the Throne you could say your not a true high king but a conqueror, which in that case anyone that conquers a region is not the true ruler, you could say for example that Nords are not the true rulers at all, in fact elves were the first race in Skyrim, the Nords came after as immigrants. I agree that to technically be the true high king you should be voted in, of all the current Jarls Ulfric has the most right to be high king, and more support from Nords than any other Jarl. At that point, you wouldn't be the hero any more, you'd be the Boss Fight. It happened to Dagoth Ur, Mehrunes Dagon, and Alduin, the prophecied God of ending the World. If not, you could call yourself 'High King', but would be nothing but a Despot.ДЄnd historically, whenever a Tyrant rose up to seize power, a Hero emerged to stop them. In other words, if it were made possible, you'd have to do it the right way. Then, you might could use that as a basis to challenge Him for the Jagged Crown, but being Dragonborn, Listener, Thane (your reward for doing all this) and all the other stuff listed in the OP would have nothing to do with it.

So no, at best you could make Ulfric High King, and hope he'd show his appreciation with a Jarldom. There's literally no way to dispute his Right.

Not the Power of the Voice, but Political Power, support of the people, and the other Jarls (Because he deposed the ones who were against him, and replaced them with supporters.) He has the Jagged Crown, and defeated the last High King in an official duel. He is the most powerful of the Jarls, which kind of require him be a Jarl in the first place. Right, but Might isn't the only thing that qualifies him.

Skyrim i am the king