Exactly. Government should recognize actual contracts that free citizens enter into according to terms negotiated by themselves.
What about adoption laws, state and federal tax laws to include not just income but also inheritance tax laws and community property laws? There's also end-of-life decisions that fall exclusively to the purview of the spouse, and no other. Would you change those laws as well?
Of course. Why should government be using tax laws and inheritance laws as social engineering tools? And was it really so wonderful that Michael Schiavo had that government-issued license that gave him power to veto the end-of-life choices of ALL of Terri's blood relatives? Community property laws? Sounds great until you're the wife who works to put her husband through medical school, then follows him to the non-community property state where the federal-government mandated National Resident Matching System assigns him, and finds out three years later, when he decides to dump you and run off with a cute young nurse, that with NO NOTICE TO YOU (and no real choice to you, even if you happened to be aware of the difference in state laws), the government has changed the terms of your original marriage, and you now have no rights to the proceeds of the medical degree you bought for your exiting hubby. And say you've stayed with your wife for the sake of the children, even though she's been a shopaholic and treated you like dirt and raised the children to be like her, and you come down with terminal cancer and would like to leave the proceeds of your life insurance policy to your sibling who's been providing round the clock care to your elderly parent with Alzheimer's for the past five years. Should you be forced to give the government a big chunk in taxes for the "privilege" of making that estate choice with your own money?
I repeat, it's really scary how much social conservatives rely on the "need" to perpetuate all sorts of unconstitutional freedom-infringing schemes to justify the party line on government recognition of marriage. Free adult citizens should be free to manage their own lives as they see fit. If one-man-one-woman marriage is really such a wonderful thing, it should be able succeed on its own, and not need to be propped up by government regulation/licensing and government social engineering schemes. People for whom marriage is part of their religious beliefs should be free to draw up their marriage contract in accordance with the teachings of their religion, not have a government-designed contract forced on them as their only option.
I think you raise some great points. I would add to your list, that "palimony" brought to the table a completely different set of problems. A person perhaps deliberately didn't enter into a marriage agreement because they didn't want the baggage, or the benefits that come with it. But, then some years later the relationship ends and they get stuck with a district court judgment that says their girl/boyfriend is entitled to half their property and a monthly stipend. Not very fair, IHMO.
On the other hand, there are social benefits to marriage that cannot be denied. Children do better when there's a nuclear family present. Perhaps the people, as manifest through government policy and laws are correct to encourage the continuation of the traditional marriage contract. It's a complicated issue and one that I frequently find myself torn.