It would be nice to have a range increase for Astonish, because it is only a 1-tile LoS now. It is very annoying for training low leveled Pokémon that learn Astonish, because of it’s weak Base Power.
If i could change it, i would make it a 1-tile spray, because when u make a scary face (like the animation), people on the sides of you could be scared too, but not behind you like an AoE. Also a not too big range, because you cant scare everyone in a wide area unless you place a bomb.
So i would be happy if you would increase the range of Astonish. The PP and such are fine, though.