They're arguing for "increased sexual activity by conservatives" which obviously means they're arguing for increase in total number of sexual encounters over the entire population.
No, they argue that this would lead to less demand for prostitutes, which would balance it out.
In effect they say that disease would spread more slowly in a graph with less highly connected hubs and more balanced number of connections per node. This is quite unsurprising.
Sure, this is quite obvious though I did not understand how they could balance out the increase, so I did not even mention this option.
The point about prostitutes was just a thought experiment, and it looks rather far from reality. The second thought experiment about Joan hooking up with Maxwell seems much more realistic, but I don't see why Maxwell wouldn't hook up with someone else the same day. Actually, the more promiscuous side usually takes the initiative, so I'd say it is quite likely that if not for Joan, some other poor girl would get AIDS anyway.
That may be the case; but it doesn't affect the theory. What's important is reducing the standard deviation from the average number of sexual partners.
Or to put it another way; to reduce the outliers who take a disproportionately high number of lovers. It is logical that this would hamper the "global" spread of disease.
This particular theory is saying that the way to do that is to reduce the opposite form of outlier - the sexual conservative.
In effect they say that disease would spread more slowly in a graph with less highly connected hubs and more balanced number of connections per node. This is quite unsurprising.