I think Romo's biggest strength is his ability to throw those intermediate patterns. He's not really good at the dink and dunk stuff and screens. I don't think he's terribly accurate on the long throws, but overall he tends to be effective.
Also, the book on Romo seemed to be to blitz him prior to 2013. We saw Haslett doing this quite a bit. I think part of it was that the Dallas O-Line wasn't reliable to pick up blitzes prior to 2013. The other part was if Romo started to pick apart the blitz, you could see where he's going with the ball and then bait him into a pick with a dummy blitz and/or coverage. The other thing is that D-Coordinators tend to not blitz as much when the opponent can run the ball because there's always that fear of the tailback getting behind the blitz and having a huge play when all the offense had to do was hand the ball off.
Plus, Romo is excellent at play action. It's very difficult to use play action against a blitz.
So, by running the ball more often (and yes, we also ran it great), we made opposing D-Coordinators less likely to blitz and that allowed us to use the play action more often. And because they couldn't blitz as much, there were less dink-and-dunk throws to keep the clock moving and to avoid Tony getting hit all of the time.
We saw this in the first game against the Skins. We didn't run the ball well and we too quickly started to abandon the run and get more dink-n-dunk. Couldn't set up the bigger pass plays and the Skins could just blitz at will. Against the Eagles in the 2nd game the run game wasn't going well either, but we stuck with the run which allowed Romo to face less blitzes and set up the big pass plays to Dez.
The final missing piece (presuming the offense is still playing well) is for the defense to become a top-10 defense. That way we won't have to worry about getting down early and start neglecting the run and being able to close out games earlier on instead of allowing opponents to hang around.
YR