I don't have a strong opinion on cloning people, but I can think of more arguments than your three that might be advanced against it.
4. Slippery Slope: Let 'em do this and talking dogs are right around the corner
5. Slavery: There are some people who are pliant and obediant by nature; and we all could use good domestic help.
6. Tyranny: Stalin finds “New Soviet Man;” makes 200 million copies.
7. Evolution: We are presumably still evolving, and cloning would interfere with that.
All right! Let's take these in turn.
4. It's not clear how this relates to cloning exactly. I suppose the idea is that cloning will lead to genetic manipulation, which will lead to talking dogs. But then we need an argument against talking dogs.
5. Slavery is a problem. However, pliant and obedient does not a slave make. Human clones, being human, would have the full complement of human rights. If pliant and obedient folks were mass cloned (a rather fanciful prospect), they would be treated with no less regard than natural-born pliant and obedient folks. You'd still have to pay them. If they were pliant, obediant and extremely smart, you'd probably have to pay them a lot.
6. Cloning, at this point, involves gestation in a real live woman's womb. So 200 million copies of anything is rather unlikely (that would be every woman and girl in the U.S. simultaneously pregnant.) However, there is a fascinating question here. If the New Soviet Man were developed (if even a possibility) what then would be the objection to communism for these folks? The main ethical problem of communism is that it is contrary and destructive to human nature as it is presently constituted. If human nature was different (this is about genetic manipulation now, not cloning), then the right political arrangement for humans would be different. (You'd still have economic calculation problems for communism, but that's a different issue.) The right way to live is relative to what kind of thing you are.
7. This assumes that evolution is a morally good thing, but it isn't. It's morally neutral. It's just something that happens, like the shifting of tectonic plate. And massive cloning wouldn't interfere anyway. It would just tend to replace natural selection with artificial selection (the process by which we get beagles from wolves.)
All of the objections are extremely fantastic; none is a plausible possibility given cloning. And even then, none approaches a compelling objection. The issues of genetic manipulation implicit in 5 and 6 are vexing and fascinating, but they are not problems for cloning.
Keep the objections coming!!!