You make it seem like Archer stole the warp drive because he just has pirate tendencies, and that Sisko did what he did in ITPM just likes to do nasty stuff. You conveniently forgot that Sisko was trying (and succeeded) in turning the tides of the Dominion war by bringing in a powerful ally, and that Archer stole the warp drive in order to fulfill a mission to save Earth, which couldn't be fulfilled any other way. What you call "weaknesses" are in this cases actually examples of those captains' STRENGTHS: making tough decisions, even when it means crossing the ethical line, in order to achieve a crucially important goal. You may say that you don't approve of the "end justifies the means" attitude, and I'd agree on principle, but fact remains that, if Sisko hadn't been a "jerk" and hadn't tricked Romulans into the war, there's a big probability that the Dominion would have won; and in Archer's case, it's even more straightforward - if he hadn't resorted to piracy (something he hated himself over), he wouldn't have been able to stop the Xindi weapon in time and Earth would have been destroyed, and most of the Human race dead. But I guess Archer and his crew could then patted themselves on the back that they remained so ethical, eh?
Somehow I don't think they'd have been doing that. Any idiot could insist that principles and laws should be followed whatever the situation, but being in a position to make life and death decisions means having the guts to weigh the priorities.Kirk could be called on questionable decisions, too, and most of them had nothing to do with his penis, and everything to do with his world views: for instance, deciding to profoundly change the civilization in "The Apple", before walking away convinced that things would certainly work out wonderfully for them. One may also question his decision to steal Enterprise and use valuable resources only in order to bring his friend from the dead. I'm pretty sure he wouldn't do it for Redshirt #52.
