Even if Alduin isn't going to listen to your reasoning, that doesn't mean that others wouldn't.
Double negative... tricky.I mean, we don't know yet what the strength of the Dragonborn is, apart from getting boons from slaying dragons. Most Dragonborns we've met so far have in fact been charismatic leaders, and not fighters. They could easily make a story with the same premise, but the outcome that the Dragonborn stops the civil war and rallies the people to fight for their world. You know, instead of fighting Alduin alone in his lair or whatever, you could start a full-scale war against him.
Maybe you'd still have to face him in person at the end, but it would be nice if a diplomatic/charismatic leader protagonist could even the odds a bit with his skills.
But I don't think it's gonna happen.
XIII - a bard in the way you're thinking of is basically part of the "thief" archetype. They do have to provide ways for each of the three main builds, but a thief in the sense that all he ever does is steal things is not one of them. The thief is the person who relies on his wits to get what he wants. In the case of a quest "go and kill X", that would mean hiring an assassin, or relying on your intelligence and your stealth to lay a trap somewhere from which he can't escape. A thief isn't necessarily a pacifist.