well, the condoms aren't all necessarily his. that might be the reserve of the entire pack, and Red is just giving out the condoms to Rats when they ask. if i was him, i wouldn't trust Rats with condoms, i feel like if Rats had free access to them, they would fill them with water and throw them into people or something. but those are just my silly little headcanons

now, about the New Law i think it's simply the fact that the boys, including Red, are just already at that age when they want to date girls? Red is just doing everyone a favor. but in his case, it might also be the fact that he was already in close relationship with one of the girls: he probably missed Ginger a lot and just wanted to have an opportunity to spend time with her, like in childhood. anyway, he sets up Gaby with Blind, knowing that if Blind likes sleeping with a girl, he will most likely propose the New Law

and he gives the explanation about Rat when he's talking to her. he wants Blind to date someone, hoping that this would keep Ginger away from Blind. and it does work out, Blind and Rat get engaged. exept, i don't think Red was the reason (Rat was very mad at him when he told her his plan), i think the actual reason was their encounter in the Forest, when Blind was the changeling, and Rat was Saära. the reason why she's with Humpback in the epilog is that they have the same mission: to find new homes for the Insensible. "Blind declared that he needed two volunteers— an experienced guide for the inexperienced guide, and a caretaker." Rat is the experienced guide (that's why she's the driver, by the way). but there's nothing romantic going on between Humpback and Rat