As for your third point.. respectfully, I do believe balance is a good thing. And while I can't always pursue them (because of the cost), there are more humane meat food choices out there.
Balance?? Why would I want that?
Humane? I think you misunderstand, it's not that I love animals, I just REALLY HATE plants.
(Yes that's a quote from somebody, don't know who to credit though.)
OK, seriously, for me it was a spiritual choice. Was reading some stuff, watched a movie and... it just felt like the right thing to do. At the time I was even thinking I would let myself have meat at family gatherings (like Thanksgiving) just for convenience and to be part of the group. But... when the time came I just didn't want to... at all. It no longer felt right. Another interesting thing, my taste in food changed over time. When I was a meat eater I would put up with salads because they are healthy. Now I actually enjoy them and sometimes feel I need one.
Once you stop meat for a while eating it again (by accident in my case when a restaurant screws up) actually makes you a little sick in the stomach. It's not a psychological thing, there are times that I don't realize my food was cooked with "unclean" pans until I get home and feel "meat sick". I really wonder if that indicates it's not what I'm meant to eat if the body has to get used to it (obviously that didn't happen when I was a meat eater). I never have to get used to any of my salad ingredients. Some may taste like crap up front but you don't get sick later from them even if you haven't eaten that food in a long time.
Regarding killing, I may come off as a hard liner but killing is killing. For me killing a person humanely (or not) isn't an option, same with animals. But to each his own. The whole spiritual aspect is very personal so I'm doing my best to just say what I feel rather than what anyone else should feel.
Josh