Fun write up of said deleted scenes here:
http://www.slashfilm.com/star-wars-the-force-awkens-deleted-scenes/
I’m sure what this guys source is, but it’s interesting to read that the lightsaber in space thing was actually filmed.
If it was actually filmed part of me has always felt that particular opening was to throw off potential plot leakers. Or, even more specifically, to identify those that might leak plot details by giving them false (read: fantastic) info.
The novelization also seems to confirm that Kylo is aware of Vader’s redemption, but that Snoke has portrayed it as a moment of weakness that resulted in the fall of the Empire, hance Kylo struggle with the light side of the Force.
Without that novelization explanation I would have also gone along with the theory that perhaps only Luke knew of Vader’s redemption since technically he was the only one in the room at the time and maybe that tidbit of information was never repeated.
That scene with the dialogue between Leia and Rey I wish was in the film to completely put to rest the notion that Rey still might be Han & Leia’s daughter. Also the scene with the Snowtroopers and Kylo on the Falcon would have been awesome. I would trade that for the Rathtars scene any day.