Motto on Doom's concepts of honor and principle. I think Doom and Reed Richards share a similar problem, they are both so intelligent that it's basically impossible for them to have a meaningful conversation with anybody. But Reed has the emotional safety value of his family while Doom was emotionally crushed by his tragic childhood and unable/unwilling to trust/love anyone.
A note on Doom and Richards, while both are virtually equals in the science, I consider Doom more well-rounded. Not just because of his magical abilities. I think Doom is just as well versed in literature, history, art and more esoteric fields. (Not that Reed couldn't become adept in these subjects, I just don't think he can muster the interest.)
I believe that Doom would have allowed her to leave and was probably mildly disappointed (or happy?) with her reaction. He's too detached to muster any feeling for a single human being.
If psychopath is the correct term, then he's the most dangerous kind. Unrestrained from emotions and morals yet completely in control of his actions.