Not arguing for or against it because the whole thing seems way too muddled for me.
But have you ever considered that the difference between your arguments (i) to (v) (with exception of (iii) maybe) is the intention of the humans involved not the suffering or the dead of the respective animals? This kind of moral reasoning is human and can be seen in other areas as well. For example, we care a lot more about the comparably "few" deaths caused by terrorism vs. the many caused by traffic, because presumably in the former there is intention of bad guys involved whereas in the latter its merely bad circumstances and chance. The result is the same: an animal or a human is killed. However, the moral reasoning is different. Just saying ...
Yes, human intent makes a difference, to some degree - shooting a tiger that's about to eat you is different from raising an animal in awful conditions to eat it later.
But there's also the issue of scale: while laboratories do kill quite a few animals (ideally in a somewhat humane fashion after a decent life, but that's not nearly always the case), the food industry kills a lot more.
I think human intentions do matter, at a qualitative level. And at a quantitative level, I hope we can agree that we're likely to kill fewer animals if we only kill them inadvertently than if we kill them both intentionally and inadvertently.
But even if you take a wholly consequentialist or utilitarian view (where the utility of animals gets some limited consideration), I would argue that eliminating (iii) through (v) is beneficial because it allows us to greatly reduce the animal suffering we cause, with minimal impact to our own wellbeing. In the modern age, pretty much no one needs fur, and certainly no one needs stuffed gorilla heads, and most people probably don't need meat. Steaks and mink coats are wasteful luxuries we can do without. However, getting rid of cases like (i) would require a great deal of effort, and getting rid of (ii) could block the path of medical advances which might significantly reduce human suffering from disease.
But have you ever considered that the difference between your arguments (i) to (v) (with exception of (iii) maybe) is the intention of the humans involved not the suffering or the dead of the respective animals? This kind of moral reasoning is human and can be seen in other areas as well. For example, we care a lot more about the comparably "few" deaths caused by terrorism vs. the many caused by traffic, because presumably in the former there is intention of bad guys involved whereas in the latter its merely bad circumstances and chance. The result is the same: an animal or a human is killed. However, the moral reasoning is different. Just saying ...