Fine, let me start listing off until I get to gay marriage. Not all of these can be easily solved, but they are bigger problems than gay marriage IMO (and I hope you will agree).
NOT in rank-order.
The huge burden of entitlement programs.
The need for tort reform.
The lack of judges for criminal cases.
Unemployment.
Excess federal power over states (such as the .08 requirement recently)
A tax system that takes billions of dollars to run.
Companies that are leaving the US, both HQ and factories.
Gas Prices.
Assaults on the First Amendment.
Assaults on the Second Amendment.
Inner-city schools where kids graduate but can't read.
1 million abortions annually.
An incompetent news media.
A drug war criminalizing millions while ignoring drug-lords.
OK, I can only think of 14 right now, but my point still stands. There are more important issues than the civil union debate.
The government should, and does, have an interest in promoting relationships that encourage the creation of future generations of children, raised by both a father and mother. (A system which has been a necessary foundation of our society, and many other societies, for thousands of years.) It should have no interest in promoting a system contrary to this which has no possibility of procreation, and by definition, would be either a fatherless or a motherless household.
Once the gov't encourages this type of relationship, it will destroy the definition of marriage, and it will have opened the doors to recognition of any type of relationship any group of people want.
If you look at a number of your concerns; entitlement programs, unemployment, public school problems, abortion, etc. They are all very closely tied to the destruction of the family. Encouraging gay relationships will only further these problems. Fix the family, difficult as that may be, and your list will become a short list of minor grievances.
And finally. Gas prices? Honestly? That ranks right there with Fox's decision to pull The Tick from their Thursday night lineup a few years ago. It's called the free market. Let it work.
Stick around, there's a lot be learned here.
