I think Roddenberry was generally conservative with tampering with human biology itself (genetics/cloning)...and while Riker did have a right to control the use of his cells, the look of disgust on his face over the existence of a clone was enough to demonstrate ST's stance.
No, it wasn't, because again, I'd argue that his disgust wasn't at cloning per se, but at the fact that he was cloned WITHOUT HIS CONSENT. Remember, the episode was an allegory on reproductive rights. It wasn't actually about the ethics of cloning, since that was a very distant possibility at the time it was written. The cloning issue was just a disguise for a statement about abortion rights, an issue that was far more current at the time the episode was written and produced. If a female character showed disgust at the prospect of being impregnated by rape, and expressed a willingness to get an abortion in those circumstances, that wouldn't mean she was disgusted at the idea of pregnancy itself
, but at the idea of having it forced on her against her will. And the same goes for Riker's reaction here.
And even if you were right that Riker showed disgust at cloning, you'd be wrong to say it showed ST's overall stance, because as I've already shown, there are numerous other examples of clones in Trek being treated as equal beings with a perfectly valid right to exist. It would be the exception, not the rule. A single example doesn't prove a pattern, especially when it's contradicted by every other example.
I never claimed cloning extinct species for any length of time was possible only that it is being tried...and I would rather watch for the results rather than claiming it's not possible before empirical evidence to the contrary.
For one thing, I never claimed it's not possible, I merely pointed out that it's extremely difficult and far from a sure thing. I didn't want people reading your post to get the false impression that the mammoth project was likely to succeed, so I elaborated on the difficulties that still remain. Don't confuse "difficult" with "impossible."
For another, you're getting the burden of proof backwards. The empirical evidence to date shows consistently that, with current technology, clones of extinct species are very unlikely to survive. Therefore, the premise that cloning is feasible is the one that has to be proven, because so far there's no evidence to support it. "Extraordinary claims require extraordinary evidence" -- Carl Sagan.