I would say...yes. It's a hard question because it depends on how you look at it. He has a very strong sense of justice and doing the right thing. However, he's not afraid to bend the law or the rules a little bit in order to make sure justice is served. If that means killing so be it but he never kills someone who he doesnt have to (and contrary to some beliefs he DID have to kill Dana and Nina). He also is willing to torture, which is bad, but its to save lives.
I'm not really sure. Although the people that he has gone after have always been terrorists, it doesn't necessarily make it right for him to torture and/or kill them. Sometimes he seems more motivated by personal interest than what is best for the country (i.e. when he killed Dana). I always understand and sympathize with him, but I don't know if I go as far as to say that he is a moral person.
Of course Jack is a moral person. He's saved the country for 8 seasons!! No matter if you believe in torture or not, he does what he does because he has a reason. He's out to save the entire country, those pesky terrorists just keep getting in the way!