I posted this in the Ethics and morality forum, but it might be more appropriate under religion:
The ethical question is whether it's the animal's suffering that makes it wrong. Could you breed animals with no sense of pain and bypass the ethical complications? Because once you can justify killing something, isn't the way it's killed is just a matter of preference? You're going to take its life whether it likes it or not. All things considered, you're hardly doing the lobster a favour by killing it softly, so to speak.
On the other hand, if you have respect for it, where does that respect come from? True respect for all life would have you dying a slow death from hunger or living of base minerals and substitutes (which weren't avaliable until recently). So are you just trying to placate your conscience?
At least in that respect, vegeterianism is a quasi-religious expression related to law and compensation, like sacrifice. It's a moral comment on the way nature is ordered and the requirements of life. Even the word "humane" suggests a mode of action that reflects on being human, as opposed to "being natural".