Old UiTC won't get any new big features, so RLD & Jack will stay as it is currently. Upcoming remaster will have reworked prostitution, so it will work a bit differently, but it's too early to get into details.
There's none. I was thinking about adding sex scene with doc, but it didn't feel right to trigger it while just trying to get new traits.
Sadly, impossible. In the upcoming remaster players will be able to tweak the .txt file to influence how RNG works for random NPCs.
Luck increases chance of literally anything happening, including events. Low cleanliness will prevent you from interacting with NPCs, as they will feel disgusted. Fame is an indicator of whether you are famous or infamous in The City, affecting some dialogues and events, but if you want to see more scenes, then negative fame is better.
Well, it was further affected by character scaling feature I believe, so under normal circumstances it's not THAT grand