Answers

NZPols has responded to my question about forcing people to go to church with a "yes":

At the level of considering the morality of any particular cause of action, I would countenance just about anything. I wouldn't necessarily do it, but I would countenance it. Being a fairly rabid consequentialist, I don't really believe that anything is inherently off limits - it all depends on the situation.

I have a certain fondness for consequentialism as well, but I'm far from rabid about it. While its a useful tool in the moral armoury, there have to be limits on its use - otherwise you run smack bang into the problems laid out by McCloskey. To some extent you can get around this by retreating to a rule-based version, but not if you allow exceptions for the specific case as NZPols does.

As for what those limits are, as a liberal I think there's a wide sphere around the individual which is off-limits to government intervention. Libertarians would justify this on the grounds of natural rights; Rawlsians from the original position; Kantians on the grounds of respect for autonomy; and rule consequentialists on the basis that people are generally happier that way. What's in that sphere will vary depending on your specific basis, but I think all four versions agree that what you believe and who you live with are well and truely covered. "Encouraging" marriage is as illegitimate as "encouraging" people to go to church. These things are simply too important to people's life-plans, their sense of self, for the government to interfere with them - no matter what the benefit.