As long as you don't go completely overboard with it, eating meat is not really that unhealthy for you. As for the moral problems, personally I only eat meat from animals that I know didn't suffer more than absolutely necessary.
No they do not. They react to stimuli, not pain. Plants lack nociceptors and most importantly brains, both of wich is required to have in order to feel pain.
So the positive effect of eating meat is that we are cruel to BILLIONS of farm animal as opposed to them being endangered or extinct? I don't really see how that's a silver lining to the meat industry.