When I was a kid, my family and I would go to the drive-in all the time. We couldn’t afford tickets for everyone, so my sister Jellybean and I would hide in the trunk until we’d parked… we’d sneak out. It’s like my home.
Edd impersonating the principal to help Eddy is one of the best things he could do for his friends.
School means a lot to Edd, or so we think, but his friends mean more to him.
This plan was all Edd’s idea. Ed and Edd rarely ever come up with a plan because they rely on Eddy. Eddy encourages his friends to lead them because as we can see being a leader really stresses Eddy out.
Seconds after doing this Edd realizes what he has done is against school rules, but he thinks nothing of this when he sets up the plan. His friends mean that much to him.
Edd grows so much throughout the series that he is unrecognizable upon meeting him in season 1.