I read the parent comment as being about the social parts of his views, which don't really seem to be about the government refraining from bothering people. Defining marriage as between a man and a woman, and life as beginning at conception, are both pretty significant (attempted) exercises of the state using its authority to resolve ethical disputes.
This was previously on amashforcongress.com; I found it searching for his views on this issue.
"I believe in the sanctity of traditional marriage, and I oppose government efforts to redefine this private, religious institution."
This seems like a safe way of him saying that the government should not have any say in what constitutes a marriage, but that he is personally against it. There's nothing wrong with disliking something, but not wanting to force your will onto others.
If that were actually his legislative agenda, that would be interesting. But I don't see him pushing that in terms of how he votes.
The government already does not interfere with the private, religious aspects of marriage. The Catholic Church can define marriage however it wants, and the state has no say in it, which is why you can't get a same-sex marriage in a Catholic church.
What's being debated is who should be recognized as married for official purposes (5th amendment rights, tax filing, survivor benefits, inheritance in the absence of a will, etc.). On that question, Amash supports the Defense Of Marriage Act, which says that the government should recognize only opposite-sex marriages, and not recognize same-sex marriages. If he opposed DOMA, and instead introduced legislation to abolish all government recognition of marriage, I'd give him kudos for that!
"What's being debated is who should be recognized as married for official purposes"
It shouldn't make a difference whether or not someone is married... you know, equal protection under the law. The solution to things like survivor benefits and the others you mentioned (and you're right, Amash doesn't mention this solution) is to simply have private contracts that people decide upon themselves.
"If he opposed DOMA, and instead introduced legislation to abolish all government recognition of marriage, I'd give him kudos for that!"
Seriously, find a single Tea Party candidate that ACTUALLY has that view on marriage. That IS the view I have on marriage, it is the libertarian view, and there isn't a single Tea Party candidate that supports that view.
The problem generally is that there's more to Libertarianism than fiscal conservatism, and Tea Party interests tend to be just as selectively fiscally conservative as the battered-brand mainstream Republicans once they're placed in power. It' s a gimmick for Republicans who don't want to be called Republicans but be elected by socially conservative Republicans that call themselves Libertarian :p