Question - how does this reduce the use of scarce resources? A cloned cow eats as much as a non-cloned cow... unless you're talking about vat-grown meat, which is, I think, a different issue.
I'm not sure it worked all that well in China, and I'm really not sure how you would enforce such a rule in most first-world countries. One of the reasons China's birthrate fell was because so many families wanted boys - and therefore aborted female fetuses or allowed female infants to die - that they have now rescinded the rules. Also, China had a few tactics that wouldn't go over so well in other countries... like incarcerating women pregnant with a second child, forcing abortions and sterilizations, and other nasties...
I think we either need to learn to live within the ability of the planet to support us or find other sources of support - the question is, will we learn in time?
See my answer to a, above - I don't think cloning animals will reduce the need for resources, and I have concerns about limiting genetic diversity by choosing to clone, rather than breed - what if something degrades the DNA of the clone line? As others have said, there are many variables here that cannot be accounted for - largely because the experiments with cloned animals and plants have not gone on long enough to determine long-term side effects. There may be none, or they may be minor - but I think it's a little early to put all the eggs in one basket... so to speak.