Will Grant ever be happy? No, not until he finds happiness in himself. He thinks his life is miserable because Kelly is not the perfect wife. I suspect that if Kelly did everything perfectly Grant just would find more fault with her. He is projecting his self-insecurity and unhappiness onto her.  
 
Additionally, why does Kelly feel the need to submit to Grant's rediculous, unrealistic expectations? Why don't they just hire a housekeeper to keep things perfect so she can do the real stay at home mother's job of raising the children? Wouldn't everyone be happy then? If that doesn't work, Kelly needs to stand up for herself, stop taking Grant's abuse and let him know that they are living in reality, not 'Leave it to Beaver' country. 
 
Furthermore, why do the people, who sent in clips shown during the show, feel the need to be the "perfect" wife or anything else? What happened to just being a normal person, enriching your life, for example, with cooking classes rather than feeling less than perfect for not being a wonderful cook? We are all born with a blank slate and the fun part is writing our own life story. Grant needs to stop trying to write Kelly's story and let her undergo some self-discovery of her own.