My idea is that the film will be edited to make it appear as if Luke had been training with Yoda in the time period between ESB and this film, which explains how Luke became a better, more powerful Jedi in-between.

You said it yourself, that Luke isn’t as powerful as the prequel-era Jedi.

Also, regarding scenes you want such as the canon comics version of Vader’s “No!”, I suggested in Hal’s thread for TRoS that they create new scenes or stuff like Adywan did with the OT; however this should require collaboration, since I don’t think you have enough resources for new scenes matching the quality of the PT and OT, respectively.

One idea I have is using the Unity game engine, I recall it being used to animate 99% of every scene in the recent live-action remake of The Lion King.