So, I did find something that the game tutorial indeed mislead you about. It says in the sticked tutorial that regular stickers are lost if removed or the fighter dies. Well, that's simply not true: if you revive them at the freezer, the sticker will still be there. And yes, it was a regular sticker, not premium (actually, my fighter had one of each and both were still applied on revival).
Also, does anyone know if all melee weapons scale with Str and all ranged weapons with Dex? I'm asking this because the knife requires Dex, but then other weapons require HP and Sta...