E.N.D Theory. *SPOILER!*

I have a few predictions of Natsu Dragneel is E.N.D or is related to E.N.D, Zeref and maybe even Acnologia.
Here are my reasons.
1) Natsu dresssed up as the 'Great Demon Lord Dragneel' is so similar to Acnologia it's scary. So Natsu may be Acnologia's relative or it's hinting that the 'Great Demon Lord Dragneel' may actually be real - E.N.D
2) Zeref seems to know who Natsu is. At Tenroujima Zeref said that Natsu has grown but is still not strong enough to kill him. That could be a hint to the fact that Zeref is somewhat related to Natsu.
3) Fighting Festival Arc - Natsu was not able to exit the guild as Freed set a barrier that people over the age of 80 were not allowed to get out. So meaning Natsu could be a very old demon. And Natsu's age has not been confirmed.
4)Igneel was not able to kill E.N.D maybe because he couldn't so he took E.N.D with him - Natsu but then got too attached and wasn't able to kill him. And Natsu doesn't know about E.N.D so meaning Igneel hid it form natsu for a purpose. I mean why else wouldn't Igneel tell Natsu about this great demon?
5) The way Silver spoke of Natsu was in such a scowl and hateful way his face was so cold and dark so he couldn't have known him while watching the GMGs. When Natsu was in the cell the words Silver said something along the line of "Natsu Dragneel of all people." And he didn't mean it in a nice way. We all know that good guy Silver has gone around killing demons. And so the way Silver said Natsu's name and his face wasn't saying that he knew that Natsu was Gray's buddy but rather that Natsu is something else.
6) Jackal didn't believe that Natsu was a human. His words were or thoughts were. "Why is a mere human making me tremble like this... No is he really human?! He has to... Impossible! It's Impossible!" The way it was said it was as if Jackal found out that Natsu wasn't human and he might be E.N.D.
7) We know nothing about Natsu's past! I mean ... He's the bloody main character for crying out loud! We have all had our share about Lucy, Gray, Erza, Happy (Edolas), Laxus, Cana and the other significant character's history or at least some background story. But we know nothing of Natsu except Igneel disappeared on 777X 7 July.
8) Zeref seems to know Natsu well and keeps saying he would have to choose between life or death. If Natsu found out he is E.N.D he would want to kill himself instead of hurt his friends.
9) Zeref says to "When one finally arrives to me will it be E.N.D or will it be you?"
10) Zeref's Black magic didn't kill Natsu.... Some say it's his scarf but maybe Natsu's scarf is a seal for E.N.D or evil magic in general.
11)Natsu's orginal concept was a spirit with horns
12)Mashima also said that Fairy Tail will change in ways we never expect.
12) It could have a major plot twist like in Rave Master the main girl character character changed dramatically
13) Gray didn't just get Devil Slaying magic... It's destined for him to fight a demon... As Silver said. A fire demon - Natsu.
14) Mashima lays out the plot in advance example Lumen Histoire and Atlas Flame. So maybe he was building up for the ending where Natsu is E.N.D