why did Rumpelstiltskin

why did Rumpelstiltskin not try to kill Shelly and MAx yet he killed the witch magically? Was it to watch them suffer and let her see her baby die?

Also what if RUmpelstiltskin used his magic to put Max and Shelly in his mouth and they are really in his mouth then what? and what stuff would Max and Shelly say to each other of the situation and how would they react?

also why didnt Shelly ESCAPE ON A PLANE To get away from him, would she have lost him?

Max also should have taken Rumpelstiltskin head miles away from his body, and then what would Rumpelstiltskin do?