Kit, while I understand you are emotionally attached to this situation, you've only brought one new factoid to any of this that might have SLIGHTLY altered my opinion. You can't prey on my emotions with empty declarations of "addict and pedo", because so far you've proven neither.
All you've talked about his drug usage is "he is blazed" which implies he's only smoking reefer. I myself don't have a problem with that, and know many successful and stable fathers/businessmen that smoke weed regularly.
And there are plenty of threads on these boards arguing the concept of kid fucking, so I won't spend much time on that note. But very quickly, he is NOT a pedo in the proper sense of the definition of the word. Unless he was diddling her in her sleep at a slumber party, or dropped a roofie in her drink to take advantage of her......I don't have any problems with 15 year old females being interested in and seeking out cock. As I said earlier those child registries have all kinds of people on them for the most absurd and innocent reasons, and what you just briefly described is a perfect example of that.
What does give me pause though is the CPS cases, although I do find it interesting they didn't act on either charge. Not saying he did NOT do it, but there are also plenty of vindictive and spiteful women that will lie and use the system while dealing with an ex and trying to get full custody of kids. Only time will tell, I guess.
And you said earlier.."is about to inherit money"...so he isn't that millionaire yet. You being so focused on him giving his kids a Happy Meal might have some nutritional merit, but at the same time he might only be trying to win emotional brownie points by giving them what they like. If he DOES have very limited visitation with them, and has a crazy ex filling their heads with all sorts of crazy bullshit and drama....I totally understand why he is trying to satiate a kid's most basic needs with "fun food", instead of putting a plate of broccolli in front of them and making them clean their plate.
As Proots just said, you can't whiteknight for this family and no matter how much moral indignation you build up inside yourself it won't help the situation at all. The cops don't care, the courts don't care, the rest of society doesn't care.....all you are to them is the guy currently sticking your dick in the mother. ALL that really matters is finite things like regular work history, proof of stable residence that SHE is providing, things like that. Leaving the country won't do anything in her best interests, and only prove to the state how impulsive/unstable her actions and life can be.