I was thinking about this episode and I think we all agree it is really bad. I think I know what they should have did, instead. They should have flipped the kid plot. Instead of kids playing the adults the adults should have played themselves as kids. It would be fun to see what Picard was like as a kid or Ro or Guinan before she was wise. I would have switched Keiko out though with another character. Maybe Worf or Geordi. At some point you might even have the kids having to pretend to be their adult selves because of the plot. I should note I would have ditched the Ferengi and just make it a character oriented episode and if they need some kind of danger or ticking clock just say that if they don't find a cure soon they will stay as kids and will basically have to grow up again but only they will be doing it in adult bodies so their "second life" would be doomed for complications and sadness.
Jason
Jason