I agree that Gil is being deliberately bereft of his family, friends, and base of support right now. Both the others have already been through this, though Gil is working on restoring Agatha's family. Both the others grew from the experience, but it's not a pleasant way to mature, even though needed for the story.

One of the things I adore about Gil is his playfulness; I hope he doesn't lose it in this arc, it would be good to see him help Tarvek play again.

I believe Agatha will help Tarvek learn that he is loved and supported, she is very loyal. Whether it ends in a romantic relationship at the end or not, I think she will continue to love him at least as a friend. It is something that needs time and experience to really sink in. Tarvek now has significantly nicer allies than he had before, something I think will make him a much happier person overall.