I didn't play the game yet but :
Concerning the error : "Script 'LE - PTBVisuals' line 133: RGSSError occurred. disposed sprite"
I had the same issue with my own Rpg Maker Vx Ace game using Press Turn scripts from Yami and figured out how to patch the problem.
Replace the line 133 by "if @count <= 0 && !disposed? ; self.flash(Color.new(255,255,255), 24); @count = 48; end"
I added the "&& !disposed?" part if I remember correctly
No more random crashes in battle anymore :)