As a divorced dad with an adversarial relationship with my Ex (many examples on this board) I read this thread in horror. Maybe I should be happy that my relationship is not this bad with my ex, though.
Susan is being an ass and Greg is the victim here. Unfortunately, she holds all the cards. Right, you can get the courts involved and it’s correct that he has rights but in practice the courts are slow and her ability to cause damage as primary custody holder is much greater than his ability to counter it as long as he lives so far away.
What’s his ability to return to California? The core problem here is the distance. As long as the children are so far away, this will always be a problem. He may have to choose between his children and his job - I know that’s harsh but it sounds like reality with his ex-wife’s attitude & obvious intentions (to estrange the children from their father).
Greg may have to sacrifice his career in Virginia if he wishes to save his relationship with his children.
The only other choice, as I see it, is to try to get primary custody - though the chances are slim. There’s sometimes a clause in a parenting agreement that forbids one parent deliberately estranging the parent from their children. The “Dad” vs “Greg” thing ought to be proof enough of her intentions (but more documented evidence would establish greater proof, of course).
He might be able to turn the tables and go for primary custody in Virginia. That’d be very hard, of course, especially since Susan’s caused so much obvious damage in that relationship so far. A judge asking the children questions might get Susan’s words in response.
Can Greg move back to California and try for half custody? It might be the only thing that would save the relationship with his kids.