4. Adoption laws will be instantly obsolete.
5. Foster-care programs will be impacted dramatically.
6. The health care system will stagger and perhaps collapse.
7. Social Security will be severely stressed.
Oh, no! Hoards of homosexuals will suddenly marry and hugely impact all sorts of social organisations.
Let's put the "dramatic impact" myth to rest once and for all, using
one of your own sources (PDF). It tells us that only a few percent of gay couples are likely to marry. We also know that gay people are only a few percent of the population.
Let's assume gay people consist of about 3% of the population. Let's further assume that about 3% of gay people are going to marry. That means healthcare and social security will experience an "impact" 0,09%. In absolute numbers that's an increase of 9 per 10 000. If that's what causes anything to be severly stressed, stagger and perhaps collapse then it is perhaps a good idea to reform them with or without same-sex marriage.
family.org via Hardenbergh said:
There is recent evidence from the Netherlands, arguably the most “gay-friendly” culture on earth, that homosexual men have a very difficult time honoring the ideal of marriage. Even though same-sex “marriage” is legal there, a British medical journal reports male homosexual relationships last, on average, 1.5 years, and gay men have an average of eight partners a year outside of their supposedly “committed” relationships.
The problem with this claim is that the average homosexual relationship is irrelevant. What's relevant for homosexual
marriage is the
average homosexual marriage. Even if it is true that homosexual men are quite promiscuous, that does not prove that homosexual men
who want to be married are also promiscuous.
If we want to conclude anything about these claims, we'll either need a comparison of heterosexual relationships (including non-marriage) with homosexual relationships, or we need a comparison of heterosexual marriage with homosexual marriage.
Many Christian Democrats (the political equivalent of conservatives) in the Netherlands do believe that expanding marriage to include homosexuals strengthens marriage, even though this is not the official party view. They also believe that gay marriage encourages gay couples to be monogamous and they think it is very important to encourage particularly gay men to be monogamous, because "everyone knows they're often not". If you also believe it is a bad thing when gay men are promiscuous, tell us what you think is a good way to encourage them not to be.
BTW: The use of quotes around 'marriage' in 'homosexual marriage' is inappropriate, as marriage law in the Netherlands is open to same sex couples: pretending that it isn't really marriage is denying heterosexual marriage as well. The Netherlands
also has a marriage equivalent like civil unions called "registered partnerships" and it has "cohabitation contracts", all open to people of all genders.