I agree about utilizing RPG elements and deepening story mode. The game could play flawlessly, but no substance for your CAW= quicker boredom. What's crazy is they could have just tweaked some (if not all) of the RTW stories to fit your CAW.
I would love if they created a story mode for CAPs that has branching elements to it. You could essentially have one story mode branch into the different RTW themed events based on your status. Have paths for when you're just starting out, for when you're shooting for various titles, faction building (and joining) paths, tag team paths, etc. Within these you could have the common elements of many WWE stories: deception, betrayal, victory, relationships, rivalry, etc, etc. It would really immerse you in the game. Especially if you could go through these paths with a buddy. Which brings me too...
Finding a way to co-op these advancements is a must. My buddy and I were all pysched when we found out they had a tag team story mode. Come to find out it's only if you use Batista and Mysterio. More co-op features and deeper stories would take away some of the staleness from the game.
I remember one of the games had it this way. You could both play through a career with varying stories generated for each character individually. It was just generic cutscenes of whichever character getting hit by a car or something. "Who is the mystery driver?" It was pretty shallow and just kind of recycled the min-stories on a loop, but it was a cool concept. This was several years ago too. Imagine what they could do with those kind of ideas now. Allow not only co-op play, but the chance for your stories to cross. Maybe a dynamic online career mode. You can choose the number of live participants much like a league. Obviously the stories would be a bit more limiting for this (maybe you each get some trash talk or team-up options for each show or something?), but it would still be interesting, I think.
I use APF as my measuring stick for my feelings on depth. Many people, particularly those who graze the OS forums love the gameplay of APF. It played a very accurate football game. There were tons of details in gameplay, but it was light on features. Without some depth, even a near perfect game becomes just a tech demo, IMO.