1. 2 dads/mums = a Nuclear bullying weapon = damged child.
Children get bullied for an awful lot of things. What colour their hair is, what clothes they wear, where they're from, how good they are at things, or even just no reason at all.
Do all children who are bullied through no fault of their own end up damaged?
2. Children need 2 parents 1 of each.
So presumably single parents should be dispossessed of their children?
What is this based on? Some kind of gender-roles idea?
3. It is artificial and not what biology intended.
Depends what you define as 'natural'. You seem to have confused it with 'common'. There's certainly evidence indicating that homosexuality is biological in nature (though nobody's sure in exactly what way).
In either case, having feelings for another person is certainly natural, and isn't something you can control.
4. Left to their own devices same sex couples can not reproduce, hence are not geared up for bringing up children.
Neither can infertile heterosexual couples. Should they be barred from adoption? Also, they're not left to their own devices, so the point's kind of irrelevant.
5. Children should not be induced into thinking that having 2 dads/mums is the norm.
Have you ever spoken to anyone who grew up raised by a same-sex couple? In my experience, they're not usually under this impression at all. For a same-sex couple, explaining this often appears to be part of what raising the child entails.