What's "advanced" anyway?
@SpeedOfLight6 Until you can answer that question, it is difficult for anyone to answer you as the question is much too broad, and open to many different interpretations.
What exactly, is "iffy" physics?
Are Matter Transporters an example of an "advanced" civilisation, or is that not "iffy" physics too?
What about Replicators or 3D printing from a molecular level. Is this possible or is it "iffy"?
Do you allow "psionics" in this "advanced" civilisation (such as such as telepathy, telekinesis, and teleportation.) There was lot of 1960's/70's fiction that believed these real, and the next stage in "human evolution," but is that "iffy"?
Presumably, not having those also rules out any magical sword weapons or a mysterious "Force" too?
Does it also rule out the existence of God, Fate and Miracles in these works?
What about AIs? And are there living machines (which then requires a more precise definition of "Life" itself)? Can a human mind be written/copied onto a living machine?
I can think of countless books, tv and films that have those things without FTL or Time Travel, but you cannot know what might be possible in the future. I'd certainly consider them equally "iffy" physics but I am prepared to suspend my disbelief for the sake of a good story that includes them.