I do wonder if part of the problem is that the manga doesn't make it entirely clear that Itachi is still the driving force behind Sasuke's decisions. There's a pretty long stretch, all during the chase/fights, when I, at least, was left with the impression that Sasuke might have chosen this purely to be stronger than Naruto. Which would be horribly childish and brat-like.

It isn't particularly reasonable to assume that Itachi has just up and vanished from Sasuke's calculations, but all the reasoning you cite is left implied rather than stated. And I've noticed that US fans, in particular, seem to have some difficulty catching implications that I suspect the writer thought were obvious.

I did feel a powerful urge to thwap Sasuke for rushing in like that, rather than pausing to ask what's up with this Orochimaru yo-ho, and with Naruto too, but, as you say, that's Sasuke.

And the adults deserve some serious thwapping, too, for not telling him straight up without being asked, once they knew he was targeted.