1. I see that your "Warrior" is level 19. Tell us more about how you find Inner Beast is not balanced. Your proposed changes makes it much much worse than original Inner Beast. It's effectively what we heal now without the 20% damage reduction.
2. Bad idea to have a skill potency to be related to an item stats. It means it'd be very hard to balance for all contents level.
3. CoS already has effectively 250 potency. You want a 5% chance to make it 350? Not happening.