When we open the door on seder night we are opening it up for Eliyahu hanavi
I actually know of a chashuva family that has someone dress up as a “ghost” (Eliyahu Hanavi) right before Shfoch Chamascha
You are not permitted to say lashon harah about yourself.
(I know the story of the Chofetz Chaim)
I actually heard that the story was made up