@Kaido:
But the arc would not be written the same if Ace wasn't gonna be Roger's son. Oda wasn't just gonna write the arc with a vacuum like that, that'd be horrible writing. Regardless of what he did with Ace, the heart of the arc would still be on him and Luffy in some way, because Luffy's the main character and Oda has never devoted an entire arc completely to third parties (upcoming Reverie might be an exception, but Luffy's past actions are quite likely to impact it)
And regarding the Supernovas, even if they were gonna first show up in the New World, that would still affect how Oda would portray them. A lot of the reason why the Supernovas have clout among the fanbase is because their actions before the timeskip helped them get off on good footing, ESPECIALLY when it came to Law. If we hadn't met Law until Punk Hazard, the plot would have to be structured much differently to make him the character that we all know.
Trying to predict how a plot would go by removing an element of it isn't nearly as easy as predicting how your family tree would end up if you went back in time and killed your grandma. Plot is built on choices, and those choices give way to more choices, from the exposition until the conclusion.
The World Government DOES want to shake up the Three Great Powers. Their actions during and after the timeskip proved that: they moved to the New World to pose more direct competition to the Yonko, and are currently planning to eliminate the Shichibukai system. You contradicted your own argument when you pointed out that the World Government wanted to take steps to shake things up if they had the power to do so.
What is true is that the World Government isn't strong enough to go up against all the Yonko without being utterly decimated themselves, so the balance is something they have to accept, at least for now. And they're obviously not gonna want the balance to tip in the Yonko's favor. But no one in it is happy about their rule being rivaled by pirates, and having to use pirates to maintain the influence they have. Akainu hates pirates like they're demon spawn and Fujitora got incredibly pissed at the balance forcing him and his men to kowtow to guys like Doflamingo. So when they had the opportunity to take a shot at one of the Yonko when Blackbeard brought Ace to them, they took it, even explicitly stating their desire to try their hand against the Strongest Man in the World.
Yeah, Ace being Roger's son certainly gave them extra cause, but we were shown how they were prepared to take the opportunity given to take down Whitebeard.
No, the Gorosei's concerns had everything to do with Blackbeard, they outright stated that he was going to do that before it actually happened and that is why they were worried. They were sullen not because there was a power vacuum in the New World, but because they knew Blackbeard would fill the one they were trying to create.
We don´t know how the arc would be written, that´s the point, but the way the summary and hence the statement is worded implies that it was close to Marineford and something like a last second thing which would not have worked.
Being devoted to Ace and Luffy is besides the point, we are talking about the justification for the arc, not the arc itself.
If he goes and says "Marines want to execute Ace because he is Ace", that would make me doubt the credibility.
But he went "Ace is getting executed because he is Roger´s son, and Roger is the worst thing that ever happened to the world (WG´s view), hence a second Roger has to be prevented no matter the consequences" and i go "makes sense".
Not really. Besides Law helping Luffy in the end of Marineford, on what grounds did Oda build his character? Heck, what was his character in Shabondy exactly? Nothing more than cool looking and cool talk, nothing more.
He would need to dedicate a few panels/one chapter to them, it´s not a fundamental change. Nothing in PH was built upon what transpired in Shabondy except that we knew him, that´s all.
Oh, they do not want that actually, unless they have a reasonable chance to eliminate all of them which is minuscule, so they are interested to keep the current situation since it prevents both the Yonkou themselves and those that have potential to maybe even rise above them from achieving even more.
The reason why they moved to the NW is because the seas are getting more chaotic due to WB´s death since he was the one who, like mentioned several times, kneeled in front of the throne and prevented, more than anybody, to get further. So his death marked the end of an era.
I did not contradict anything, like i said, unless it´s something that would grant them a huge advantage and the power to change the world, eliminate piracy, they are interested in keeping the status quo.
You are not getting it. Happy or not is irrelevant. It´s something they have to live with and it is a far more favorable than chaos in the New World since you can´t predict what will come of it. That´s why Luffy shaking things up will be a huge thing.
That´s false. The motivation was never to target WB, if you think that, you have not really understood what Marineford was about, read chapter 550 again. The Gorosei are moderate, they shit themselves when a weak Shichibukai is taken out because of the balance, and the same applies for Sengoku . Bottom line is, it is stated very clearly "you were protected by WB for the last 2 years, we could not do anything but we have to take you out before you reach your potential, even if it means going to war with WB". Nobody was eager to take a shot at WB.
Not even remotely. Just to quote "the balance of powers have fallen to a terrible state", that´s their ibggest worry. They simply point out taht BB has the biggest chance to fill that void, they are not worried that he will fill that void, a seemingly small but big difference.