I also thought that he might offer his heart willingly to Pan. I would of liked to have seen more background/or flashback of Felix, but they managed to show it loyalty to Pan quite well in the little that we did get.
Maybe if they ever decide to tell more of Hook or Bae or Tink’s backstory Felix can come back as a guest star.
I really do think Felix loved Pan. It’s very sad and just goes to show how terrible Pan really is.