All the data is added by the users. If adding those is not against the rules feel free to do so.

There is no specials season, and one cannot be added as the series was cancelled. If you can create the season, I can add the episodes.

You need to set it as Returning series to add new seasons, then set it back to cancelled.

That's usually locked but isn't for prodigal sons. I've added the specials season and set it back to cancelled.