Defensive end may as well be outside linebacker especially at your size so that transition should be easy. As a lineback should focus on your lateral speed. Think rode and cone drills will help you with that.
Being physical will also help you out as well. As a safety first and foremost you need to work on open field tackling and running. Learning to take good angles as well as becoming faster.
As a defensive end the first 10 yards is really important but as a safety youre the field general so need to be able to sprint all across the field.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.