The significance of The Numbers are too widespread to even begin to list here. Their overall meaning is the numbers of each of The Candidates, as we will find out much, much, much later in the series.
I'm not sure living out the rest of his life as a demigod on the island is exactly the luckiest thing to happen to anyone, But I think Hurley probably ended up with the best deal of all the passengers all he wanted to do was help people with the money that he won, and with the island's powers he ended up doing just that.
Our first glimpse of the mental institution where Hurley spent so much time is in this episode. We see his "friend" Dave that he hallucinates later on the island. Who is not seen is Libby, who is later revealed to have also been a patient at the institution. In fact, her character had not even been invented yet.