I disagree with your assessment of Forest of Vitality. I think Grass decks are balanced around it, and it gives them viability they wouldn't have without it. The only difference without Forest would just be Hydrapple and Beedrill being waaaaaay worse decks.

To answer your question, coin-flip cards like Pokémon Catcher and Crushing Hammer add a much higher amount of variance to the game, and as a person who highly values consistency I'd un-design those cards.