As a parent OP’s story makes so little sense, what if there was an alternative explanation?
Parents get a lot of training about grooming. In one scenario sexual predators target vulnerable women, often abuse victims (including care leavers), though any vulnerable individual can be targeted - irrespective of IQ, level of education or socio-economic status. Predators deploy various strategies to win their target’s trust, e.g. becoming the ‘perfect’ partner or parenting figure the target never had growing up. They aim to gain access to the vulnerable target’s children. The grooming can take place over weeks, months or years, as the predator patiently works to gain control. Hiding in plain sight, he remains connected to other child molesters, sharing abuse content, and tips on grooming and avoiding getting caught.
As others have pointed out, there are too many red flags in OP’s story. To be clear, I am definitely NOT stating that OP is a victim of a grooming sexual predator: I know nothing of her, other than what she posted here, I am saddened by what she's described of her situation, and wouldn’t want to upset her further as she (hopefully) shelves her adoption/fostering dreams to put child protection and welfare where it should be, i.e. FIRST.
But what I’m finding particularly alarming is that OP’s story is consistent with grooming. Vulnerability, due to a background as an abuse victim in the care system. Convicted sex-offender partner taking a guilty plea while claiming innocence (better 5yrs on the SOR for the crime you got caught for than a custodial sentence for an as yet undetected crime?), being in a network of sex-offenders, saying he’s willing to walk out of his child’s life so OP can foster or adopt (access more vulnerable children?). OP believing him fully and defending him so staunchly, when everyone else is horrified. OP’s insufficient regard for the harm that a vulnerable adoptee and her own DD would be exposed to in her family (“10% risk is OK!”), and for the harm experienced by the child abuse victim(s) whose photos her partner’s friends were sharing around. General lack of understanding that child protection is the imperative here, and that ANY risk of exposing a vulnerable adoptee to a sex-offender is completely unacceptable from the get-go. As PPs have said, it suggests someone with clouded judgement... Highly educated but vulnerable people can fall for the “perfect partner and parent” grooming act too.
I sincerely hope for OP’s sake, and even more so for her DD’s, that the above is completely and utterly wrong. OP you’ve been through a lot, with a challenging background of abuse and care-experience to recover from - there’s a reason more than 1 in 4 mums with children placed for adoption are care leavers – and you are clearly a survivor, having made it to a law degree. But add to that having a convicted sex-offender as a partner, with whom you share a now vulnerable child, and you already have more on your plate than many people can handle. You’d have to be an incredibly well-adjusted adult and a super-parent to successfully safeguard and raise a vulnerable adoptee to adulthood in addition to coping with all the above. From what you’ve been writing here, you’re quite some way from that.
Instead of gearing up to fight adoption agencies and LAs in Court to put a vulnerable child in harm’s way (good luck with that), you may want to reflect on whether the path you’ve chosen as a mum remaining with and defending a convicted sex offender is consistent with being an independent-minded, outstanding, child-focused parent. And take an honest look at what else might be going on in your interactions with your convicted sex-offender partner.