1) I don't have any ethical issues with any organism killing another organism to help sustain their life. And by the way, you don't either. Unless you've spawned the ability to photosynthesize light (in which case all props to you), your body is sustained by killing off biological life, breaking that life into macro molecules, and using that to sustain yourself. You make a distinction that you are ok with extinguishing the life of Bacteria, Protozoa, Plants, and Fungi, while I do all of that and add on animals. I'm not sure what the difference is there if you are arguing that life is sacred because if you believe all life is precious and shouldn't be extinguished, then you can't exactly live. Which btw is a totally feasible and admirable viewpoint - Jainism takes an approach like that and I respect that religion. I just personally don't see self actualization as giving all up earthly desires and extinguishing my life as a part of nirvana.
2) I don't have an issue with domestically raising a species and treating it purely as a thing for me to eat. To me that's actually a better way to do things, because domestic consumption ensures that I'm not eradicating wild and unique ecosystems of life. Btw, unless you forage for all your produce, you don't have an issue with that because if you eat vegetables from a grocery store you are consuming a highly genetically modified organism that has been evolved purely for your consumption. The fact that grocery bananas don't have seeds should disturb you greatly if you have a problem with evolving organism for your benefit. The distinction again, is that you have a problem with domestication of animals, but you seem not treat other organism as purely something for you to eat.
To put into your own words, it's a matter of widening your field of ethical concern from the arbitrary "Animals" to all organisms. Otherwise you will sound like, say, a white-supremacist racist talking as if only white people matter, all others have no value, mean nothing except as they can serve whites. (I have to use these analogies to try to get you to hear what plant-eater arguments sound like to me)