I have been a vegetarian now for over 10 years. I love it and do not miss meat at all. I despise it now actually. 
Well, you're joining a tradition with ancient Indian and Greek roots. Those civilizations also despised meat!
Yes, I have read into those histories. They believe that animals are also God creation and are His children as well and should not be killed especially for our own tongues.
Generally a policy of nonviolence toward animals, yes. But modern vegetarians advocate nonviolent treatment of animals for any purpose, not just consumption.
Yes, that is a modern things for sure because in old history they also made things from animals but only after the animal died a natural death.
Its resurgence in the 19th and 20th centuries is likely due to the increased industrialization of the world. Greater food availability and all that.