Part 1 is here.
6. Random sampling will occasionally produce unrepresentative samples.
Significant deviation of a sample from the population sampled is in fact very rare. For example, in a population evenly split between men and women, the chance of having fewer than 40 women in a sample of one hundred people is less than 2%. The chance of having fewer than 30 woman is less than 2 in 10,000. And the chance of having 20 women or fewer is less than one in a billion. The current U.S. Senate (a body of 100 people) has 20 women. It is the highest number of women senators in U.S. history.
7. Since there are many population characteristics, the sample would be unrepresentative according to some of those.
Again, because the chance of significant deviation is so small, even if many characteristics are considered the chance that any of them would show significant deviation is small. For example, over one million characteristics would have to be considered before it would become likely that a group which is a minority of a third according any of those characteristics gains a majority in a sample of 200.
8. The lucky few who are selected will often serve personal or narrow interests rather than those of the people.
For policy to be approved by the allotted body, it would have to win a majority. Interests that are personal to one or to a few delegates would not be able to meet this criterion. By the time a proposal wins a majority is has to serve so many personal or narrow interests that it becomes representative.
There are special situations where the allotted body, as a body, has a narrow interest, such as when considering the compensation for the members. For those special situations some special arrangement needs to be set up. For example, such issues may be handled by a separate body or reviewed by an independent jury.
9. Many people would not want to put their lives on hold for a few years while they serve their allotted terms. If only some of the those sampled actually serve the sample is no longer statistically representative.
This is a question that should be settled by experience. It would certainly be a problem for sortition-based government if allotted seats are not generally accepted. The logistics of service should be set so as to be as inclusive as possible. In particular, the compensation for service should be generous enough so that for the large majority of people service would likely be financially rewarding. In addition, an attempt should made to accommodate specific needs that stem from the circumstances of the allotted.
It may very well be that, given the opportunity and generous compensation for their time and effort, few would give up the chance to devote a few years of their lives to changing their society for the better (as they see it), and at the same time to win the appreciation and respect of those who know them (and possibly of many other people as well).
10. Even among those who accept the nominations many would not put much effort into studying the issues facing the nation. They will not be able to come up with informed and considered decisions.
This is a version of objection #2. First, the assumption that the average person will not put much effort into their public service is not substantiated by the facts. Normal people who find themselves in a position to improve their community often go to great lengths to do so. But, again, even if we accept the negative assumption and take it for granted that the allotted delegates will not put much effort into their public service then it is still clear that their special position will allow them to reach much better informed and considered decisions than voters do.