Sorry man, I'm a vegetarian sympathizer, and I liked your post, but I think you're off here. Avoiding tissue damage does not equate to the conscious experience of pain in plants, inviting that comparison is asking for trouble imo.
The reality is that is the biological definition of pain and the aspect of plants havin some form of neural system is just being unravelled in cutting edge botany.
No living thing is pleased with being killed and consumed in its prime unless that act of sacrifice is part of its reproductive cycle.
I'm not saying anyone (except inuits or other people living in extreme arctic environments) should eat a mostly animal product diet, just te opposite I tell most of my omnivorous patients to eat more veggies and fiber.
But I do strongly beleive that the ethical arguments for veganism are horseshit and are based upon the fact that vegans don't want to admit that they too are killers and kill for food every day.
Peter Singer argues that it's ok to slaughter a fish for food because they experience pain differently than land animals and are merely "vessels for emotion".
Personally I feel that Peter Singer is a deuche and the ethical argument for veganism is riddled with the worst kinds of spiritual arrogance. It's all killing. Take it all seriously. Thank the onion before you pull it out of the ground and treat the act of uprooting as seriously as you would treat slitting the throat of a live goat.
If you as a consumer in a capitalist society want to change things you will do far more to change the market by supporting sustainable local farms that specialize in free range / grass fed / humane livestock while eating a diet that is rich with fresh produce than by never spending any money on any animal products.
I work in natural medicine in Los Angeles and deal with malnourished anemic raw vegans everyday that I go to work.
"Don't tell me about diet, my diet is perfect! I'm a raw vegan!" (Said by a woman who eats only one meal a day with almost no protein content, has not had a period in seven years due to anemia / malnutrition and is coming to me to help her get pregnant.)