1. The state of captivity is a creation of modern mankind and there has never been any kind of captivity in free nature.
2. Holding animals in captivity for their entire live, often in narrow cages just to produce cheap meals, is the spawn of arrogance.
3. There seem to be strong parallels to the Morlocks (H.G.Wells, 1885) when considering today's human society's behaviour toward the weaker creatures.
4. Everybody consuming products of the imprisoned creatures is a keeper and responsible.
First, I would like to suggest a very interesting book by Peter Singer you may like, called Animal Liberation
. Peter Singer essentially states that there is no reason why animals should not at least have an equal consideration of interests. As far as captivity and the use of animals as a means of sustenance, Singer suggested that an animal should be compared to that of a small child. If it were acceptable to hold a child captive (as well as most other things like testing, etc.), then it would then be acceptable to hold an animal. To not consider animals in the same light as, say, the child, it is a form of speciesism, racism, etc. Likewise, there is a philosopher by the name of Tom Regan who, in The Case for Animal Rights
, posits that animals, as subjects of life, are entitled to basic rights (which are honestly much the same as Singer's). Singer and Regan both support an extension of rights to animals. And in the case of captivity, the rights surely do extend.
Now as far as the points you have, I draw some opinions. In the case of your first point, that in the case of the nature of captivity, because it does not exist in a state of nature, then there is something inherently wrong with it. Suppose the contrapositive, that because there is something which does exist in a state of nature, then there is something right with it. Survival is one thing that could be brought up, among quite a few other points. As to point #2, I do think there is something inherently wrong with the fact that an animal would be incarcerated without the freedom of choice only to be killed for "cheap meals." However, humans need livestock the way chickens need feed (or whatever they would eat in nature LOL!). Chickens would just as soon protect their sustenance the way humans would. On your point #3, I remember that the Morlocks in The Time Machine
do not as much represent the top of the food chain abusing the substance they eat, but rather form a link in a greater chain in the grander scheme of things. The Morlocks themselves die out and the Eloi become bunny-like creatures. Irony? Maybe. As to point #4, I do not agree with the extension of accountability. Honestly, there is not a person alive who is not guilty of consuming products of an imprisoned creature. If you have ever had a flu shot or any of a myriad of other things, you have had at least bear some sort of "responsibility." Does this mean we are all guilty? If so, then what do we do or how do we censure ourselves for it.
One thing that should at least be amusing to many is the fact that if animals are not consumed, then there must be some sort of substitute which is. Most cases, it is plants. But if animals deserve rights, don't plant's as well? They have no means of defending themselves (in many cases) from the predation of humans, who hold them captive in small gardens only to raise them to a level of maturity and then consume them. I wonder of Singer would agree that this is a form of Plantaeism?