Gay Marriage - the Anglican Mainstream Response

Oh dear, oh dear. I am struggling to keep my blood pressure down and not write the whole of this in capital letters. Why? Because I just read this on the Anglican Mainstream Website... I'll quote their points in green:

i. Who will really be harmed by gay marriage? Heterosexual married people.
Even now, trendy married 'straights' are being influenced in their views of what constitutes marriage, and types and levels of commitment to their spouses. If married gays can and do allegedly ‘have it all’ — the wedding ring but also sexual freedom — then why can’t they as well?

No - we are each responsible for our own behaviour. Scaremongering and blaming others is not appropriate. Many heterosexual and homosexual people are unfaithful to their partners, this is not a pattern of behaviour that the church endorses. Surely offering the opportunity for folks to marry and make a commitment is a good thing?

ii. Who will really be harmed by gay marriage? All our children.
Because it will become part of the cultural air we breathe that marriage and family is at heart all about adults’ desires, and not those of far more fragile, vulnerable children who need and want their own mothers and fathers. As Jennifer Roback Morse insists, 'Rather than attaching children to their biological parents, same sex marriage is the vehicle that separates children from a parent …'When we come to our senses 30 years from now and realize that we have perpetrated a grotesque injustice, not a single child born fatherless or motherless within a same sex marriage will get his missing parent back.'

If we take this argument to its natural conclusion then we should not permit anyone to adopt nor to use artificial insemination nor to be a step-parent. This is not about homosexuality, it is a reality for heterosexual couples too. Life is complicated, but I am pretty sure that the most important thing for any child is to be brought up in a loving home. I am also sure that there are plenty of children who are brought up by their biological parents for whom this is not the case.

iii. Who will really be harmed by gay marriage? All of us who care about family and sexual morality.
Lining up behind gay marriage advocates are other voices for other and far more alternative ‘orientations’ and sexual minorities. Did you realise the ‘LGBT’ acronym is just the start of a new ‘sexual alphabet’? Over the course of this year, Bishop Gene Robinson has publicized affirmatively the existence of these other sexualities. (6)

I really dislike slippery-slope ethics. It basically says that we should discriminate against group A who are broadly okay because if we don't then we won't be able to discriminate against group B who are not okay. More scaremongering, I feel. In addition there is an argument about HIV on the Press Release:

Fifth is the impact of gay sex on the health of its practitioners. I focus on only certain pathologies. The latest survey results from the prestigious US CDC are worrying. It reckons that 4% of the male population can be considered as MSM (men who have sex with men) and yet this population accounts for almost half of all HIV/AIDS cases. One in five MSMs have HIV, and of those, nearly half were unaware of their HIV status. Over a quarter of a million MSMs have died of AIDS in the US alone since the start of the epidemic.

I don't see what this has got to do with the issue of gay marriage at all? Yes, we know that more gay men have HIV than in the general population. Presumably gay marriage is a good thing because it is encouraging monogamy. Is it me, or does all this feel like pure prejudice and spurious arguments?