OK. One more round.
1. Is marriage a right or a privilege?
Marriage is a right. But you seem to make a distiction: you seem to think that civil marriage is a privilege. But if there is a right to contract, then there should be a right to civil marriage which, after all, is just a contract between two people.
You seem to think that this right exists in today's political and civil society, but I disagree. There are hundreds of subtle and not so subtle ways that being (legally) married and not being married can never be the same; even with the expenditure of any amount of legal fees. Even if every non-government institution treated a legally-single "married couple" the same way as a legally married one (which they do not; which I would like, but do not claim a right to), there is always the various levels of government. Governments use the coercive power of the State to suppress the rights of single people. Stealing more from them. Preventing certain relationships and contracts. Etc.
For instance, the protection of the fifth amendment about testifying against oneself protects married couples, who obviously have a special intimate knowledge of each other's affairs, from having to incriminate each other in court. This seems very reasonable, otherwise, communication between spouses would be stifled. That protection does not extend to legally unmarried couples, no matter their 'personal' relationship, powers of attorney, etc. I can be thrown in jail for not testifying against my partner of 20 years, if asked to.
All this 'drawing up of papers' begs the question, is legal marriage a right if you have to pay for it? Would freedom of religion be a right if you were taxed for it? What if the government said I could have a church, but only in a town 400 miles away? Then one could make the same argument: "Well, you can have your religion, you just have to drive further to practice it, but you have the same 'rights' as everyone else. (Quit complaining.)" I think any reasonable judge would say that there was an infringement on my right to practice my religion, in that case, since I am not allowed to set up a church in my own town. This is just like saying: "Well, you can 'simulate' marriage by hiring a lot of lawyers and drawing up papers covering every contingency of death, separation, property ownership, etc., so you have the same 'rights' as everyone else." (So what if your employer, your hospital, your children's school, your state government and the federal government, etc. don't recognize that private 'marriage' contract you keep waving in their faces. Quit complaining.)
State governments offer a "standard" contract for marriage. Being a standard, getting married is a much easier and surer thing. Can my partner and I use that contract? No! We tried to sign-on to the California version on Feb 16, 2004, but on August 19th, 2004, the government cancelled our contract, without consulting (or even so much as notifying) us. So, our right to enter into a contract was denied by the State.
Finally, don't forget that several states are going even further. They are passing laws and constitutional amendments that specifically prohibit gays from any of the 'benefits of marriage'. These laws are being used to eliminate any type of 'marriage' or 'domestic partner' benefits previously granted in those states, such as insurance for employees' partners and equal parenting rights (another good example of where legal marriage is different from single-with-lawyers).
David, we both would rather see rights expanded rather than contracted when moving towards equality. So, the question is: Is allowing same-sex marriage both improving equality and increasing rights, or the opposite, or is there a conflict between the two?
As previously pointed out, we are talking of equality under the law, not to be confused with equality of outcomes.
I would contend that allowing same-sex marriage moves both towards greater equality under the law and towards greater liberty.
Consider two cases for me and my partner: a) our only option is being single, and b) we have the choice of being single or married. Now, if we thought that being married was a poor choice, we wouldn't have to take it under option 'b'. We can always choose to stay single, which is our only possibility under option 'a', so our liberty is hardly being decreased. We only get married under b) if we think it is to our advantage, therefore our liberty is being increased. Since most every other group in society is being offered option 'b', then by offering it to gays, equality is also being increased.
Ask the question: Would [L]libertarians be for putting the miscegenation laws back on the books? Would this increase or decrease liberty? Would this increase or decrease equality? This is really the same as the same-sex marriage question, but with a different set of actors; otherwise no different. If you would not be comfortable with re-outlawing inter-racial marriage, then why would you consider the outlawing of same-sex marriage OK, but for a different set of biases?
BTW, I don't equate 'same-sex marriage' and 'big-government libertarianism', as implied per your Rothbard article reference. In one case we are increasing liberty and the other reducing it. I am not asking for higher taxes, higher government spending, more war, more regulation, or anything of the sort. I just want lower taxes, lower regulation, etc. Now, don't try to say that my (potentially) lower taxes are a decrease in your liberty... I won't buy into that argument.