I think thinking that Abrams is responsible for the plot weaknesses and key scenes is a little naïve. There were likely dozens of people working on the script. Abrams had a part in it, but I don't think the plot would have been much different with another director. Disney decides where the franchise is going, not Abrams.
The first of the act of the movie was great, pretty much flawless in my opinion. But the movie started struggling almost as soon as Han Solo entered the story. Although still very enjoyable, from that point on a lot of the progression of the story seemed forced, contrived and rushed. The script should probably have been…
I'm sure Disney had their say, but Abrams Kasdan and Arndt wrote the script. And I don't think Disney mandated it take place on a desert planet, have a droid looking for its master with secret information, leave said planet on millennium falcon, have a guy who is basically darth vader, another death star, another death…