There's so much wrong with these paragraphs, but let's just focus on this:



Considering they are two different personalities, I imagine he would feel just fine. As the movie showed, Stark realized his inventions were responsible for hardships in the world, and he decided to do something to fix things (becomes Iron Man). He doesn't have mopey about it.

Plus, designing weapons doesn't automatically make you the moral equivalent of Dr. Mengele, since those guns and bullets can be used to protect lives as much as take them.