In order to understand how The Force Awakens fits in with the PT and OT you need to believe that the force is NOT in balance and hasn't been since the end of Return of the Jedi. This goes back to my belief that for balance to be achieved you need equal parts light and dark....yin and yang. With Luke representing the light side and no Sith to represent the dark side the Force is certainly not in balance!
My theory is supported by the Star Wars ring theory here: starwarsringtheory.com/ which is a worthwhile read for any Star Wars fan.
So how does the ring theory help us figure how The Force Awakens fits into the saga? Lets begin by looking at the two main characters, Rey and Kylo Ren, last year many sites were calling Daisey Ridley's character Kira, now she's being called Rey. I'm going to say her actual name is probably Kira Rey (ray...of light) and Kylo Ren (rend...break or divide) is her "brother", I don't believe this is a coincidence, I also believe Kira Rey and Kylo Ren represent the light side and the dark that Andy Serkis mentions in the first trailer.
So how does Kira Rey and Kylo Ren fit into the saga? I've heard a few theories the most prominent being they are the off spring of Han and Leia Solo. I think this is partially correct, what has been going on in the Star Wars saga for a long long time? I'll give you a clue....it's in the title....yes WARS, and what do wars create?
Luke was an orphan, under the guardianship of his aunt Beru and Uncle Owen, Leia was also an orphan under the guardianship of a Senator, the actions of their father, Anakin Skywalker set their future destinies.
But what about Anakin Skywalker? Was he the the creation of manipulated midichlorians by a Sith or an immaculate conception of sorts....the force made flesh? I believe it's the later. Anakin Skywalker/Darth Vader was the light and dark sides of the force which was best visualized in season 3 of The Clone Wars in the Mortis story arc.
As of this writing popular opinion is that Kira Rey is the daughter of Han and Leia. Perhaps Kylo Ren was under the guardianship of Han and Leia as well but left them at a young age. Let me elaborate a bit, at the conclusion of RotJ the rebels struck a major blow to the Empire with the victory at the battle of Endor, with the death of the Emperor we all believed the the republic was reborn, well we know now that's not the case, but the playing field between the Empire and the Rebel Alliance isn't as disproportionate. I believe shortly after the events of RotJ Han and Leia got married but soon the reality that the Empire wasn't going to just crumble and wither away after Palpatine's demise Leia returned to her destiny of following in her mothers footsteps and devoted herself to the political arena, years past and the hopes of having children of their own slipped through their fingers like the sands of time, but an opportunity crossed their path to have the family they dreamed of and it also was a calculated politcal move that would bolster public opinion for Leia. They adopted two war orphans. Kira Rey Solo and Kylo Ren Solo.
But in times of war records are lost, and these two had no records of who their family was or where they came from. But in this case they didn't have any records of their past because they weren't children of humans, like Anakin they were created by the force, but unlike Anakin who was the embodiment of the light and dark sides of the force, Kira Rey and Kylo Ren each represent one side of the force.
Now here's something I find very interesting! I recently read somewhere that Kylo Ren believes he is Darth Vader and tells his subordinates such. Is he that in awe of the legacy of Darth Vader that he has convinced himself he's Darth Vader? Is he using this to instill fear in those around him? I don't think so I honestly think Kylo Ren IS Darth Vader. If you accept that Anakin Skywalker/Darth Vader was one and the same Light and Dark when he died and returned to the force what then?
Will we see a force ghost of Anakin Skywalker in the ST? I don't think so, why? Because Anakin Skywalker/Darth Vader has been reborn as Kira Rey and Kylo Ren!
Remember the whole story of Darth Plaugeus at the opera house? If my theory is correct Darth Sidious had the answer sitting right by his side and never realized it! How ironic......