After he'd had their email he did think about replying, but decided instead to write another story. He felt confident with this one they wouldn't be able to accuse him of spying on them. What he didn't consider was that he was giving them ideas! Ones they obviously enjoyed trying.🙂
Could Ben be GW? Ben is very much a novice at these activities, so I doubt it. Coud possibly be Jake though...
As you say Ben does have an accepting and enabling father, perhaps because he and his wife have a poor one which he thinks has affected Ben's confidence. Thus he's trying to help rather than hinder things.