I echo your thoughts MD. Having recently returned from Italy, I can only describe the wealth of the Catholic Church as obscene.
Further to the cattle v crops discussion, single crop agriculture not only requires large amounts of water, but to be profitable, it also requires the use of pesticides and large amounts of chemical fertilizers.... but somehow it is cattle that are vilified.
My cousin is into food ethics. It's a really complicated argument, cattle need lots of land but as you said the lesser land can be used for stock often. Unfortunately there are issues with factory farming with poor welfare standards for animals, unethical use of hormones, antibiotics and chemicals. Even things like Mad Cows disease was due to feeding them cattle products making them cannibals. The only other examples before that were in the pacific islands where people ate each other and had a similar outcome.
I don't think the world would be able to support a full vegan diet for all. I know a guy who does consultancy for companies setting up organics and specialty foods and he said that rushing things to market to keep up has meant there are a lot of issues with the highly processed vegan substitute foods they make. Especially with China rushing to make up vegetable protein bulk and no really caring about where things like peas are grown. He said one company was cropping next to a battery factory with mercury, lead and cadmium in dangerous levels in the soil.
Eating free range organics is better for everyone's health and the environment and also animal welfare but again you couldn't have everyone eat that way cheaply.
I think it at the end of the day you should just do your own thing with out being wasteful or profligate and you can't go too far wrong. Things like plastic packaging and overly processed and sweetened foods are just as big an issue. Yo really can't fix everything in the world but you can do things with your consumer dollars that promote things to be better. I live that way but only because it suits my ethics, I don't expect anyone else to do it.