On the subject of gay adoption, I think its wrong because it just undermines the natural order of the family unit and replaces it with an "anything goes" approach which ultimately, is detrimental the children.
Do you want to tell me what "natural order of the family unit" you're referring to here?
Surely you don't mean the nuclear family unit, something that at best has a few hundred years of history behind it.
Your argument makes two major errors, the first as I've already pointed out is in assuming that the social arrangements that YOU are used to and grew up in are "natural", so if the norm when you were a kid was a mum, a dad and 2/3 kids this is "natural" and "normal".
Any brief study of history or anthropology will tell you that such family arrangements are socially constructed. Go back 500 years and see how many households you find, even in Britain, that have that sort of nuclear structure.
The second is more philosophically fundamental. You fall victim to what moral philosophers call "the naturalistic fallacy". That is, even if your chosen family model, the nuclear family, WAS the "natural" way of living, you have made the assumption that alone is enough to make it morally desirable.
And that's bollocks. Go down that road and we're back to being tribal hunter gatherers pretty fucking quickly.