In the end it is the material you are working with and the skill of screenwriters that allow actors and directors to turn a story into a compelling screen piece. Unfortunately, whether it is the book or the screenwriting, this story has slipped in Starz's Tudor trilogy. Laura Carmichael and Harriet Walter give excellent performances and should receive their credit. Frankly, they carry the show. This third installment is more a romantic then historical fiction.
As others have pointed out Henry was 11 when Catherine came to court, not some love sick 16 year old. If you want the Catherine/Henry/Boleyn story, which I expect Season 2 to be, watch WolfHall for first rate historical fiction and acting.