But this would eliminate a very important piece of information, that Vader can feel Luke’s presence, and that he realizes that the Emperor was right, and his son came to him.
If he thinks this is just a rebel shuttle they might just shoot it down. I see no reason why Vader would let them land on Endor.The only thing this changes is that Vader questions where the shuttle is going because it’s breaking from the normal route. It doesn’t alter the fact that Vader then senses Luke.
And they don’t think it’s a Rebel shuttle, it’s an Imperial cargo ship and the older clearance code they have “still checks out”. None of that is changed.
I believe it could make the audience feel that Vader is asking about the shuttle because he senses that it is off course, not because of Luke.
Yes they would think. Unless you cut the following dialog:
Piett: Shall I hold them?
Vader: No leave them to me. I will deal with them myself.
Clearly they know.