I agree there are no rules about the number of godparents, indeed the parents can be the godparents themselves but it's traditional to have at least three, two female and one male for a girl.
I can't fathom why Pip and Toby are scrabbling around for a second male (Riccardo) unless it's a clumsy attempt to bring a new character into the drama. Why on earth would Pip want someone she has never met as godfather to her child unless the writers are trying to make a point about the futility of it all when neither parent is a practising Christian? Well done, Ben, for standing firm.
It doesn't sound like prison has changed Freddie one bit. Still as annoying and not a shred of remorse for all he has put his family through.