Question: Why type of propulsion system does the Endurance use? It took 2 years for them to reach Saturn from Earth. Once they're in the other galaxy, the ship appears to travel between planets in mere hours/days. Also, it appears that the smaller shuttle craft was launched from Earth on a Saturn V type rocket, but later when leaving the surface of other planets, they have no such system.
Question: When the crew gets struck by the gigantic wave on the Miller's planet, CASE is shown to be able to morph into a wheel-like form, and rescue Amelia. If CASE is actually that fast, and that "versatile" to hold things while running, why can't he actually just move around the surface, and survey the wreckage of Miller's ship. That would have saved a lot of time, wouldn't it?
Question: SPOILER ALERT: What exactly happens in the end, does Cooper actually die and the Tesseract and the Cooper station were just parts of his dream? Please let me know if I might have missed something because the explanation that he travels back through the wormhole to Saturn does not make sense to me. He must have been sucked inside the Gargantua and died, surely?