If you're thinking along these lines, I'd like you to consider two very important points:
The biggest challenges in giving up meat are for young people who live at home with people who still do (this is a serious challenge), and people are used to eating out a lot, especially if they don't live in a major city (vegan/vegetarian options are scarce in some places). For everyone else, especially for people who cook for themselves, giving up meat is not the sort of epic change people imagine it to be. I did it cold turkey, and alone, without any kind of support, in an omni household.
Never in history has it been easier to find recipes, support, and information on veganism than it is now, with the Internet being what it is. In terms of what to eat, this is not a problem.
So, while you're pondering the questions you're asking, why not experiment. Try one week without any animal products. Or at least try vegetarianism - giving up actual animal flesh...I am perplexed by how big of a leap people find this. Veganism requires some recalibration, but vegetarianism...quite easy.
And I say this just because, other than pizza, really, I just don't miss the rest of it. And I went cold turkey. And I went cold turkey in large part because of the questions you yourself are asking. I got into a spat about animal rights here the other day, and it really is irrelevant (to me) to this central point:
Given the reality that there are plenty of things to eat other than meat, many of which are surprisingly tasty, the question becomes: other than the fleeting pleasure of eating a specific food, is there any really good reason to keep eating meat, even if you can't answer all of the details that come with considering animal sentience, animal "worth," etc?
You can continue to ask the questions and ponder them if they interest you. I'm just suggesting that you need not reach a conclusion before at least experimenting with a change.
There are multiple stories on reddit of people trying out vegetarianism or veganism just as an experiment and sticking with it past the end of the experiment, sometimes because they suddenly feel so much better physically, or because they find they enjoy the food far more than they thought they would.