On Adoption

I was reading lots of comments on Bush's "flip-floping" article. While doing so, I noticed three very controversial notions appear in someone's comments. -adoption, artificial insemination, and kids from previous marriage.
I personally raised up in two biological parents. Around me, I know some people who are raised up in the different environs as I, and I know a couple of problems that they encounter in their lives.
What I'm going to write down is NOT meant to harm or undermine them. Just remind it in mind...
As everybody already well know that "adoption" itself in system and in reality contains two opposite value-should I say it's ambivalent. Adopted children are usually either those who given up from their parent(s) or left from one or both of decease, under the circumstances those children themselves didn't want to be so. There are some inevitable reasons related to this. So they have to be raised by someone and it's very necessary thing.
Negative aspects are because they are going to live in other's household, they are very much likely to face some difficulties. In case their fosters are very descent and people of integrity, we don't think about the risks any more. If one of their fosters are (which is worst of all evils) paedophiles, what would occur? If one of their fosters are homosexuals, what would occur?
At any country in all times "paedophilia" is a very serious crime, which often causes its victims to have psychiatric problems later on their lives.
What about "homosexuality"?, which is not regarded as crime in many countries. homosexuality between same sex oriented people is just fine, but if some homosexuals are forced to have sex with straights, what do you think it's acceptable?
I believe so-called "same sex marriage" incur one of worst possibilities contains single or both factors mentioned above.
In case of artifitial insemination, since the children don't know who their biological fathers are, and don't live with their fathers, the problems similar to adoption are likely to occur.
On kids from previous relationship too, the situations are the same.
If children cannot choose their parents and parents can choose their children, it's a miserable thing. Except for an inevitable situations( accidental decease of parents, etc.), we all are responsible for our biological child....which is needless to say...though.