There is no doubt in anybody's mind that when the threat of the dragons is removed, the Charr will begin their war against the humans anew.
Actually, I think there is reasonable doubt. It may be a line that Smodur is holding back from quenching to appease the hardliners, but given how generous he's being with the truce terms when they could just have been "okay, we'll just hold off on fighting one another until the common enemy is defeated", I think he is aiming for a longer-term peace and possibly alliance.
Keep in mind that the charr political climate, especially with regards to foreign policy, is very different to what it was in GW1. GW1 charr had an uneasy sometimes-friends-sometimes-enemies relationship with the norn and pretty much viewed anyone else as enemies or potential slaves. GW2 charr have developed a history of friendship with the norn, business relationships with the asura, and while still militaristic generally aren't the omnicidal warmongers we saw in GW1. Practically speaking, there's not much to be gained by continuing to bang heads against the literal stone wall of Ebonhawke, and ceding territory that was never going to be safe for the charr while the war continued is a small price to pay for ending that war.
Additionally, having a common enemy, and especially fighting side by side against a common enemy, is a strong uniting factor. Like Logan swearing not to fight charr at the end of EoD, resuming hostilities will probably be a much harder sell when a significant number of charr have had experience fighting alongside humans - even those that aren't part of an order will likely have the opportunity to do so through combined efforts in Blazeridge or the Fields of Ruin, the Pact presence in Fireheart Rise, or the likely campaign against Kralkatorrik.
Regarding the breaking of Stormcaller... I'd personally regard that as an unwise move if it was done by the three playable legions, given how useful it would be against the Flame Legion. As a result, I suspect it was the Flame Legion that instigated that before the rebellion occurred.
I for one hoped that orb you capture from the krait would have a bigger impact on the fight with Zhaitan.
As you said, Zhaitan (and the other dragons) are portrayed as forces of nature, but when we fight him he just sits there while we throw fireworks at his face..
The orb was actually very important - it meant that the Pact had one area in the vicinity of Orr where Zhaitan couldn't just raise undead from anyone who fell. While we don't see it, I suspect the Pact made sure whenever possible to bring the bodies of the dead back to Fort Trinity so they could be safe from corruption.
It was in the Vigil story line, a orb that would defend people from getting undead.
Everyone sees it in the Fort Trinity personal story quest.
It's unrelated to the Vigil - whether you get that or not is determined by what you tell the Pale Tree is your greatest fear. Surprisingly enough, whatever you say is your greatest fear is what ends up happening!
I'm not racist irl, and it doesn't carry over to other games.
It's just, in my experience with GW2(And I had no issues with humans before the game was released), I noticed human players will stand on top of me while I'm downed and not res, or they'll hit a target that isn't important to the objective of an event, or they'll talk about how they did everything right and everyone else is an idiot. There was even a human necromancer who did absolutely no conditions whatsoever and tried to tell me I'm the idiot for expecting otherwise.
I could say the same thing about warriors, guardians, and other 'easy to play' professions (and I say this as someone who mains a guardian and a mesmer). The more popular options have a tendency to have the highest quotient of selfish players.
It's one reason why I'm generally much happier to see an engineer or even an elementalist (despite how poorly elementalists perform when soloing) than a warrior or guardian. Engineer and elementalist players, at least in the more difficult areas, tend to show a proficiency and perserverence that more than makes up for any shortfalls their profession might have, while the heavy professions seem much more likely to play poorly and/or abandon other players. From my experience, in fact, the effect of profession is stronger than the effect of race.