Firstly, animal rights...
I believe in animal rights...to an extent. Kind of. See, most serial killers start out by killing animals for kicks, and them move up. This kind of shows that we think about animals having human characteristics to an extent. How we treat animals reflects how we treat humans, since both feel pain, it is just a matter of self awareness. So casual cruelty is wrong, and at least some care should be given to treating animals humanely. However, needs of the self-aware part of the population trump the non self-aware, so we still gotta eat, and that's fine. We eat cows and pigs because we breed them for it, and at least show the respect of killing quick. But animals like dogs and cats in the western world are around specifically to be a sort of stand in for human beings. Technically, torturing a dog isn't exactly wrong, but it shows some pretty serious problems in your head. But in those places where there thought of as food first, eating them is fine. Of course, this rather significant cultural gap leads to a bit of tension, since no one anywhere would eat a pet. If a pig were treated as a pet by a family, I bet that that family would not eat the pig when it died. But I am unaware of any serious attempt to stop other cultures from eating the animals of there choice, excepting endangered animals. Sometimes, a cultural gap should be accepted, not crossed. So in essence, killing a chicken is not as bad as killing a dog not because of the animal, but what it says about the human doing the killing.
The second part is a lot simpler. I would be mostly vegetarian in theory, there's vegetarian dishes that taste like there meat counterpart. There's 3 reasons why the big switch doesn't happen. First off, there is a taste difference, especially depending on the dish. Its been bridged enough so I would normally only eatnormal meat occasionally, but its still there. Secondly is that humans have been programmed to love meat. Early, hunter gatherer humans would benefit from eating as much meat as it possibly could. As much as we possibly could amounts to much, much less then we eat today. We would occasionally get lucky, and it would be in our benefit to eat a large amount of delicious red meat which provided us with a lot of wonderful, life giving calories. Nowadays though, we don't have to be lucky to get meat. Our diet has evolved much faster then out dietary desires have. I'm sure that Humans will evolve and adapt, and become much closer to vegetarians, and vegetables will be the most appealing part of what we eat. That spinach will look far more delicious then that prime rib. And it will only take a few million years. But the absolute biggest reason were not all eating vegan chicken instead of real chicken, by far, is simple economics. I recently bought some vegan chicken nuggets for lunch. They were very good. They were also about 6 Ounces for 4 bucks. That night, I bought some real chicken from the meat department. Pound of chicken was a little under 2 bucks. So yeah, generally, I will go with the real chicken. I have no choice.