I think your hypothesis in the third paragraph is a little off. To take an example, many (if not most) Westerners are strongly against the farming of cats and dogs for meat, which is commonplace in some Asian countries. Those farmers are not breaking any promises of taking care of their animals, so this Western opposition must be coming from the fact that we think that cats and dogs have an intrinsically higher value than the animals we eat here.

To respond to some of your other points:

* I am against the torture and killing of animals for food when other nutritious and more environmentally-friendly food is abundant. This does not imply that animals and humans have the same moral value. I have yet to meet a person who claims this, so this always seems like a straw-man argument to me.

* On the same note, I have no problems with people keeping pets as long as they take good care of them.

* Minimizing suffering does not mean that you would prefer the body not to induce fever to fight disease, because that would lead to more suffering in the future.

* We should both be maximizing happiness and minimizing suffering as far it is possible.

* Also, why involve religion here? I am sorry but I fail to see your point in the fourth paragraph.