Here's my take on it all.
Trailer 2 Narrator: IS Luke Skywalker. The reference to my father has it as opposed to had it refers to the theory of the living Force held by Qui Gon Jinn who was Obi Wan's Mentor who was Luke's first mentor, and Yoda is also a proponent of this theory of the Force because he makes his home on Degobah, a planet teeming with life, he was friends with Wookies, creatures close to nature on Kashyyk, and the fact Yoda tells Obi Wan he can teach Obi Wan how to commune with the Force and communicate with the Force Spirit of Qui Gon in Episode III. As such all three predecessors to Luke were believers in the Living Force and not only Qui Gon can manifest as a Force spirit,but Obi Wan learned how to as evidenced by Empire Strikes back and at the end of Return of the Jedi we see Anakin was permitted to manifest as a Force Spirit which means he too held to the teachings of his Master in the Living Force theory before his fall to become Vader. When he was redeemed he returned to that, and because he was the chosen one had the power to manifest as a Force Spirit even if he did not study as much as Qui Gon Yoda and Obi Wan in how to do so.
SO to say "My father has it" is just saying that Luke believes in the Living Force and likely communes with his redeemed fathers Force Spirit from time to time so to Luke, his father is not really gone. Neither is Yoda or Obi Wan.
Next, "My sister has it" again refer to Ep VI when he speaks to Leia. It's Leia. Simple enough.
"You have that power too" is also something Luke said to his sister Leia because she said her brother has a power she didnt understand and could never have. But it can also conveniently be applied to his children and to Leia's as Luke also said in Ep Vi that "The Force is strong in my family."
Where does that leave us in Episode VII?
***WARNING! SPOILER ALERT.*** Do NOT read any further about my theory if you do not want to read spoiler theories!
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Kylo Ren is Luke's Son. He took the name Kylo Ren to hide his identity as a Skywalker. Since he admires his grandfather when his grandfather served the dark side, and since Vader shirked his name Anakin to become Vader, (i.e. "That name no longer holds any meaning for me." - Vader to Luke in Ep VI), so too has Kylo shirked the Skylwalker name and becomes Kylo Ren. The plot mystery is what is Kylo's name before he becomes Kylo Ren? It is _____ Skywalker.
I think it would be a perfect reversal and continuation of the family plague that faces Luke and his family. First his father needed to be redeemed....now his son needs to be redeemed.
Luke is now a bearded recluse Jedi Master living in exile, like Obi Wan, and Yoda, has to come out of exile and train new Jedi to face his son because just like Obi Wan did not have the heart or strength in old age to battle Sidious and Vader, neither does Luke have the heart to kill his own son if he cannot redeem him, so he carries that secret and burden and will not tell his young Jedi protege who Kylo really is. Perhaps Luke tried to train his son to become a Jedi and his son fell from grace which lead Luke to go into exile because it pained and hurt him so. And as such, there will be a great reveal...
"I am Luke's son." - Kylo.
I think Kira Rey Solo or Rey Solo or whatever her name is, is Han and Leia's daughter and she may well be Force Sensitive but because she is like her father Han she wants nothing to do with the politics and "hokey religion" of the Jedi and Sith but like her mother Leia demonstrates strength and agility and skill for combat like her mother and father and excellent reflexes on account of her force sensitive nature.
It may well be that Kylo Ren wants to recruit his cousin Kira/Rey Solo to the Dark Side, as they probably had a good relationship growing up and he still feels that bond. Like Anakin as Vader, Kylo still has some manner of heart. He is a Skywalker afterall, albeit twisted like his grandfather Vader in his perspective by the Dark Side.
If the rumours about Han being killed by Kylo and being an adversary of Kylo are true, it would make sense to me that Kylo needs to rid Kira Rey of her father's influence so he can turn her to the Dark Side. If Han protects his daughter from the First Order and this Sith who he does not know is Luke's son and his nephew, then a pinnacle fight could happen between them. Perhaps Han has also killed many members of the Empire and the First Order and frustrates Kylo's efforts to sieze control of the Galaxy through the First Order and as such he has earned enough hatred for his uncle to want to be rid of him for more than one motive. One, to remove his barrier to his cousin Rey, two, to get revenge on Han for being an adversary. Han likely dies trying to rescue his daughter from the clutches of Kylo and he either never learns who Kylo is or Kylo demoralizes Han as he dies by making the reveal that he is Luke's son just to screw with Han's mind as he dies...seems like a very Sith thing to do.
Kylo has Vader's helmet as a relic of admiration for all his Sith Grandfather accomplished as the Sithari and the Chosen One. For Vader was indeed both. Plus if Kylo is learning from Sith Holocrons of Darth Plageuis he would recognize his Grandfather as being the Sithari as Plageuis had the Power of the Dark Side to create life. (Refer to Palpatine's conversation with anakin in Episode III about Darth Plagueis).
Plagueis created Anakin/Vader in the womb of Schmi his mother, because by Schmi's account Anakin had no father, he was born of the Force itself. This would cause Kylo to admire his Grandfather as a Sith Legend and Darth Plageius as a truly powerful Sith who knows the secret of how to create life, a secret Vader lusted to know to save Padme from his nightmarish premonitions of her death but a secret he never learned. Kylo wishes to take up that mantle and master the one Dark Side Secret his Grandfather could not to prove he is more powerful...which is a common Sith obsession.
Now, if Kira Rey Solo is rebellious and wont take the Jedi Mantle...who shall Luke train to confront his son?
Fenn. The ex Trooper. There is a scene where Fenn is seen with a Lightsaber strapped to himself as he runs with Rey.
Thus, "The Force Awakens" in someone NO ONE expected it would....Fenn. And Luke sees this and sees hope to turn the tide of the Dark Side with Fenn's help as Fenn can become the next generation Jedi with no family ties to Kylo. A perfect hero to confront Kylo. And like Obi Wan, Luke won't tell Fenn the whole truth about who Kylo is just as Obi Wan did not tell Luke the whole truth about Vader (i.e. he is Luke's father).
Perhaps Luke hands the light saber to his niece Rey at one point hoping she will learn the ways of the force but eventually she gives it to Fenn who is seen in a scene in the trailer with it strapped to his side.....Again taking into account Rey is a supporting hero with Fenn and recognizes his power in the Force and supports him on his path to become a Jedi as she is a competent Force Sensitive in her own right but wants to continue to "do things her own way" rather than become a Jedi herself ...chip off the old Solo block.
The robotic hand on R2D2 is Luke's. He has come out of exile and perhaps the lack of flesh on his robotic hand is due to many battles fought in the past 30 years. Recall that Anakin had a very rudimentary robotic arm when he first lost his hand in Episode II when he married Padme and by Episode III he had changed /upgraded his robot hand. Who is to say Luke did not take an upgrade to his robot hand in the 30 years since the Battle of Endor? Seems plausible enough to me...
Or it could be Kylo as he was being trained to be a Jedi by his father Luke before his fall to the Dark Side. Could be a flash back scene. Wouldn't be the first time poor R2D2 found himself in the presence of a Jedi destined to fall to the Dark Side...First Anakin, then Kylo
aka ____ Skywalker?
All of this seems to give the latest installment of the Star Wars Saga a nice neat tie in to everything done previous to it and would be literary story genius, and also seems more Disney Appropriate than any theory involving Kylo being the progeny of incest, which I dismiss as totally ridiculous.
How is THAT for a wicked Episode VII plot line Theory??