I agree wholeheartedly with you on that topic.
If the woman during her marriage, has been unfaithful, and as a result of that she had a child, she has the moral obligation to share this information with her husband, regardless of her feelings or lack thereof for her husband at this point. Face it, if she was in love with her husband she probably wouldn't have cheated on him. I see women all over that think it's ok to cheat as long as they don't get caught.... I personally don't know how they can live with themselves, knowing that they're not only putting themselve in sexual danger of any STDs out there, but also their husbands, who hopefully care for the family materially.
If the woman knowingly declares her husband as the father of the child, although she is almost 100% certain that he is not, there should be legal ramifications for that. If the husband raised this child as his own for several years, there are emotional, relationships, love, trust formed between the child and him and this should continue no matter what. The child CANNOT be put in the middle of a dispute between 2 adults. The child didn't ask to be born into this situation. The child can't be held responsible for the lack of responsibility of an adult.
As far as the DNA test and the law is considered, there should be the possibility for the husband to be released from direct financial responsibility toward the mother of the child, but he will still be responsible for the DAD figure for the child, that should never change. There should be a stipulation that from the time of discovery there should be 2 years that the paternity suit should be filed. This would give all parties concerned ample time to discuss and think about their goals and all possible outcomes.
I'd suggest that the mother should seek financial support from the real biological father, if she still rembers him, and if not, oh well.
The (ex)husband should not be held financially responsible, although I think it would be a good deed for him if he were to establish a trustfund for the child and until the dispute is clarified, the child support per se should go into this trustfund (could be used later on as college money if he and the child decide to do so).
The (ex)husband needs to continue his relationship with his child, because he's the only Dad this child ever met and associated with. Her refusal to be adopted by her mother's new husband shows me that there are deep seated trust issues and fear that this child is dealing with towards men. No child should EVER have to deal with this. WE as adults are responsible for the well-being of our children - well-being means all around, financially, emotionally, mentally, etc. If we can't vow this to our children, we ought to not have any.