So what you're saying is if the captain doesn't like you because you're Zionist they can remove you?
I think he would face discipline from his airline after the fact, but in the moment, he is in charge.
This is pretty wide of the mark. They have a lot of authority, yes, as it's the flipside of the flight's safety being their responsibility. They still aren't allowed to assault a passenger, say, or commit tax fraud, or needlessly break the air laws.
Also, while the plane is en route? As in, the captain throwing someone out of the plane mid-flight?
And yes, the captain's authority is greater while the plane is en route compared to on the ground. En route the captain can divert pretty much anywhere if they think it's the right thing to do. They can dump fuel over the ocean or even over houses if they believe the alternative is worse. When the plane is on the ground realistically all they're going to do for anything is deplane everyone, either at the gate or via an evacuation.
What are some things Israeli settlers shout before they murder Palestinians? Shout a couple of those on a plane and see what happens.