Okay, trying to be more organized here, so bear with me. I'll start with what I think are the easiest points first.
(1) My complaining has little to do with you and more to do with having to either find what I typed before or retype it. My preference is retyping. Further, I was more interested in convincing premio that he was a theocrat than having this debate with you and/or Symmetry, which was what the original whining was about (on my part).
(2) The benefits associated with marriage are absolutely not rights. If the government took away the ability for a spouse to make a life decision on behalf of his or her wife or husband, there is no recourse for the spouse. If the government decided tomorrow to legislatively determine that spouses could not make life decisions on behalf of spouses, Husband X couldn't petition the court to reverse the new legislation under any constitutional principles. Rights (with some very few exceptions, benefits springing from marriage is not one of them) exist as a result of the Constitution and violations of such rights must be brought under constitutional principles. I can name a number of examples from your list that are simply not rights by any stretch of the imagination - the ability to file a joint income tax return; the ability to share in the deceased spouse's property (each state has a different rule); alimony payments. These are not rights, they are benefits or privileges granted by the government based upon the government-recognized status of two people and their contract with each other. If the government were to take away any of those benefits, they would not be taking away rights.
(3) Your example of building a new building versus installing wheelchair ramps is a good one and will help me with my illustration (or at least make you understand where I'm coming from). From a political theory standpoint, I'm essentially a constitutional libertarian. I believe that the U.S. federal government is only permitted to regulate and control that which it is expressly permitted to regulate and control by the U.S. Constitution. By providing regulations and benefits associated with the contract of marriage, apart from the benefits that marriage grants as a contract in and of itself, the government is overstepping its bounds from a constitutional perspective and from the perspective of my own expectations of the government. For me, marriage is a religious institution (Catholic in my circumstance). It is a religious contract (for lack of a better phrase). For some it may be a love contract. For others it may be a business contract. Or it could be some combination of those things. In any event, the government recognition, regulation, and provision of benefits with respect to marriage is one element of a host of other items that I do not believe the government should do.
So let's take your building example. The building you reference (marriage) is one of 5,000 buildings sitting in a town that is meant to house 5 buildings. I want to tear down that marriage building and 4,994 other buildings because the town was not meant to fit, nor should it fit, 5,000 buildings. Putting a ramp onto the marriage building is not going to do the job for me.
Furthermore, and unrelated, allowing gays to marry is like putting a ramp on the building and then not putting braille on the signs. The building is still going to be exclusionary of other groups that may want to enjoy the benefits of the building, but cannot precisely because the building exists as it currently exists. Marriage benefits as they currently exist (i.e. as a grant of the government) are ripe for being able to exclude certain groups of people, which is why, as I've indicated before, blacks and whites couldn't get married and gays can't get married. The Constitution ostensibly should correct this problem but our court system is at the mercy of the whims of the general public, in the same way as the legislature. Ultimately, gay marriage will not be acceptable federally unless a majority (or more) of the people in the country think it's okay. That is anathema to my vision of what the government should be. The only reason the majority, Congress, the president, and the courts can refuse to give benefits or federal recognition of gay marriage is because marriage is regulated and benefits are determined by the government. If the government didn't regulate or benefit marriage, the problem would not exist. As part of a larger effort, on my part, to shrink the role of federal government to its constitutionally acceptable levels while also, necessarily (necessarily I say!) letting people retain the most freedom, I would do away with the institution of marriage as a government-recognized institution.