I have a couple of ideas to throw into the pot!

• Melfina gets a plugsuit rather than being naked (i think that either Jim, Gene, Melfina herself or someone else would develop the plugsuit) But there would still be fanservice
• The Outlaw Star would have a new form (maybe whenever something happens to the ship or an entirely new ship that functions like the Outlaw Star but with new features)
• New Villains (either Space Pirates, the Galactic Government or a new entity or faction), New Allies, Sudden Twists (like sudden reappearances, Tragedies and/or Betrayals), Returning characters like Suzuka and Aisha (duh!)
• Giant Mechas like a Mechanized version of the Outlaw Star akin to a Gundam (well, it was animated by Sunrise)
• Melfina getting much more Character Development (probably could be a bit stronger both physically and emotionally)
• Melfina Clones (just something wild maybe an evil Melfina Clone (which is a bit cliche))
• Alternate Universe versions of the main characters (If Rick and Morty did it well then why not Outlaw Star)
• Spoofs and/or homages to other Sci-fi properties or even anime series