I totally agree about the suffering animal. I mean it's a judgement call, I don't think it's immoral to choose *not* to kill a suffering animal, whether because you think it might have a chance to live or because you don't feel comfortable taking a life. But taking a life to end suffering is certainly justifiable if the intention is there.
I know there are multiple schools of Buddhism and some different ideas about eating meat. I find some of them to be a bit more internally consistent than others, but then I'm not an expert on it so I could just be misunderstanding. But even in the vegetarian sects, if you're going to argue that killing a plant is wrong, then I feel like it's a bit of a cheat to say that it doesn't count to eat it if you didn't kill it yourself. I'm sure that in predominantly Buddhist communities, for example, there are people who buy or harvest extra food to give to the monks that they know will need to eat. If the monks weren't depending on the community for food, those plants wouldn't be killed, so they are still indirectly responsible for the killing of those plants. It's the same argument that people make against buying consumer goods that involve the exploitation of vulnerable people (or animals). As long as there's a demand for those products, suppliers will continue to produce them with no motivation to change their practices. You can't escape the bad karma by distancing yourself from the original action. In my opinion, anyway.
Just a disclaimer, I'm not trying to disparage Buddhism; I think most religions and philosophies are similarly valid prisms through which to view the world, mostly organized around the same central moral themes and mostly differing in the details. I have more of an a la carte approach that draws from many different belief systems because orthodoxies and organized institutions don't resonate with me personally, but that doesn't make them any less valid than the ones that do. Just want to be clear, when I debate concepts of Buddhism, I'm not saying that they're wrong or that other people shouldn't follow it, only that it those particular aspects don't resonate with my personal world view.
I totally agree that the world would be a better place if more people were open to listening to other people's worldviews. That's one of the reasons I enjoy debating philosophy and religion, when people are open to it and don't interpret it as a personal attack. I think most of us agree on most of the important things, and the relatively minute differences are just reflections of differences in priorities, values, preferences, lifestyle, opinions, etc, which aren't worth getting too worked up about because they mostly come down to personal preference, and without which differences the world would be a pretty boring place.