Pippin/Fridge

The reason that this is the actor playing Pippin's first time in the role is everyone else who's ever played it commited suicide at the end.
I could be wrong on this, but Catherine is a widow. Each of her "husbands" was a Pippin that was incinerated in a previous show. She finally stands up to the leading player because she is tired of losing those she loves.
"No Time At All," Berthe's song about living as much as you can during the time you have on Earth, isn't meant to show Pippin the meaning of life. It's a warning about the finale.
The Leading Player responds to Pippin's near-breakdown at the end of "On the Right Track" by laughing and telling him he's, "on the right track". Pippin's breaking down is the right track to wanting to commit suicide.