Clearly she isn't a pacifist who thinks it would be wrong under any circumstances to use weapons for war, but that is not amoral as such.

Yes, that was the wrong word. Hardcore pragmatic, maybe?

I think the reason why Tony makes such a hard turn wrt weapons is his giant ego, which won't allow him to displace responsibility as being just one person in a complex system, but thinks of himself as central, essential and able to control outcomes on his own.

That, and also Yinsen basically telling him "be someone worth sacrificing my life for". (And that Yinsen does die for him is a big shock.) Which, this being Tony, doesn't result in him, say, building up an aid organisation (though later movies always mention charity work he also supports) or something like that, or taking a political interest in the war in Afghanistan, he has to become a superhero. Which I think you can make a reasonably good case may be the result of Howard canonically not shutting up about Captain America during Tony's childhood. Someone good, someone worth admiring = Steve Rogers, superhero. Ergo Iron Man.

...which is just guaranteed to get incredibly messed up once Steve Rogers turns out to be alive and is around to interact with, naturally.