I was going to quote my faves on what you just pointed out here, but then my reply would be even longer than yours, haha. So I will just say that I couldn't agree more, you hit on the character flaws of Jack perfectly. I like that he is broken, it makes him seem mortal. He is not in control of everything and there is no way to fix him, not really. I love that, it makes him seem very real to me.

And Ianto, yes, I agree that he gets no credit where credit is due. I do not see him walking around like a love sick puppy. He is also pretty broken, like you said, with plenty of emotional baggage. Their relationship reeks of complications and that makes it all that much better.