Hello Eme! I read your original post. What was it? 7 months ago? Maybe you’ve been updating?
Most of your requirements are cool with me. I am a big time Harry Potter fan, it is the only book series I read more than once. Instead of HP, I had some ideas about Percy Jackson or Firefly that I would be willing to try. Actually, it isn’t Percey Jackson, but an RP based on Assassin’s Creed: Odyssey. I guess Percy Jackson and ACO both have Ancient Greece in common. There is the parallel. We could either take on the roles of Alexios and/or Kassandra or maybe original characters set in that universe. We can chase down the Cult of Kaos members while skirting around the Peloponnesian War waging around us between the Spartans and Athenians. Maybe bump into Medusa, the Minotaur or the Cyclops.
If you are not up to a bit of Ancient Greek History, there is always Firefly. The book I am writing is set in a similar time frame as Firefly, but with a very different setting. Firefly was very dark and gritty which works for me. My book's setting allows that earth will continue to grow and succeed in an ever expanding universe; it is more positive. I actually saw the movie, Serenity, just recently. I never saw the TV show and wished I had. I loved the movie. When the show was on TV, I was working for a railroad averaging 72 hours a week and didn’t have time for TV. Even a story like Firefly could progress in a similar manner as Odysseus’ Odyssey in Homer’s tragedy if we write a sufficient amount of obstacles. We may even be able to borrow some of the mythical creatures from Homer's Odyssey and apply them to a 26th century setting.
EDIT: Keep your cookies. ;)