The missing sprite is from the first tutorial. It looks like your player is just a white smile at the center of the orangey 4 pointed star.
If you don't want to use HP numbers, then I'd remove it from the tutorial dialog. Having it there had me looking for where it was shown and wanting to know the numbers for my own characters.
I'd hide the placeholders for the current demo. If they don't do anything, and don't need to be visible, then might as well hide them to reduce player confusion.