I don't regard the Atlas Shrugged movie project as an attempt to release a piece of entertainment. I regard it as a propaganda campaign. (remember, propaganda can be true).

As such, I think some themes need to be emphasized that were glossed over a bit in the first two movies, either because the dialog was cut, or was delivered too briefly.

Obviously ASp3 will deal with Dagny's time in the Gulch. As Galt is showing her around, he could once again reiterate why he left the 20th Century Motor Company.
But I think it's important to show how life in the Gulch differs from the outside world. The class-less-ness. (such as a successful banker running a hog farm). Also, a clarification of the oath might help. Without a context, the oath can easily be taken as a declaration of selfishness. I think Dagny put it best in ASp2; "I won't be a slave; and I won't be a slave driver". That's the oath, IMO, in a nutshell. I swear upon my life not to use people, nor to let people use me.

A minor nit; as things run down, cell service will become spotty in the outside world. Clothes will become shabbier, food more scarce.

I think another important thing to make sure makes it into the 3rd movie is how railroad shipments are being manipulated based upon political considerations, not actual needs or financial considerations.

In "Go Tell the Spartans", there's a scene with a staged riot. The story explains how the rioters attempt to manipulate the media by giving themselves razor cuts and provoking the milice and then cowering in front of the cameras when the milice try to drive them back.

I think something similar might be useful during the "riot" at the Rearden factory. The schism between his actual workers and the imported rioters would be important, too, IMO.

I think the whole of Project X could be dealt with briefly, providing more time for more important topics. It might even be eliminated, except for references in the narrative.
Likewise, I hope any porn scenes are left out of the 3rd movie. They serve no purpose.
In the olden days, in ASp1, they would have shown Dagny and Hank go into the same bedroom together, and either the light would go out, or the door close, and then it would be the next morning and they were having breakfast. This saves precious seconds from a story already crushed for time, and allows the imagination to work on the details of their sexual exploits (for those minds that would care).
Likewise, the entire scene after the Taggart wedding could be cut. It's irrelevant. They could cut right to the scene where Lillian confronts Hank. The fact that he was with Dagny the night before could be easily inferred from him walking in in the am, Lillian asking her questions and saying, "You have her all over you".
Again, precious seconds saved, narrative tightened, and modern immature idiots are not pandered-to, something of which I approve.

I don't need to tell anyone that Galt's speech will have to be carefully edited. It's going to have to be modified to fit within the movie schedule, yet still hit all of the important points. I think it can be done, because much of his speech can be made redundant.