The Problem with GP isn't that he has too much damage.

GP feels better as an assassin to most people. Whatever. Do you.

What's not okay is that his heal is (At rank 1) 50 + 15% missing HP +90% AP + removes all CC. This makes him too safe and unfun to lane against at all ELOs.

What I personally think is that the base healing should be removed so it feels like he is being punished for using it just to remove CC at full health.