Mhhh. If I recall correctly, those were posted on Mangafox in February 2012. So a few days before the start of the Uchiha Bros. vs Kabuto fight. I just dismissed it at the time, thinking it was yet another troll trying to look like he knows the end, but now that I look at it...
Remember, February 2012. So those bullet points are spot on to some things. But then again, all the original poster of the rumors said (his name was Tobi777 iirc) was pretty general. As in pretty vague, the kind of thing nobody really gets at the time, and that can easily be reinterpreted.
Let's look at the confirmed points.
"6. We will see the previous Hokages again before the end of the series"
This one wasn't necessarily hard to guess, but it's still interesting to note. Had he said "they will be resurrected" instead of some vague "we'll see them again", I might have been incline to believe him more.
"9. Kabuto's interest in Sasuke is that he wants the Sage's mental energy/spiritual energy, which allows the Sage to invent any jutsu he can imagine."
That wasn't extended upon, so I can't say, but Kabuto definitely had an interest in Sasuke. Still, it was pretty predictable, what with Kabuto wanting to emulate Orochimaru. Again one of those "I don't know" kind of points
"10. Though Zetsu was cut down, his importance in the manga is not over, expect more to be told about him later on.."
Yet again something that was an easy guess. We didn't know a lot about Zetsu, so it was obvious he'd be expanded upon. Plus he didn't mention TWO Zetsu.
"13. Tobi is both Madara and not Madara at the same time, his situation is similar to Kabuto's"
Now this is one of the "easily reinterpreted" points. But, it does make you wonder, what with Tobi being "half Madara Zetsu" and all. The comparison to Kabuto is what somewhat no-sells it, though.
"15. Itachi will meet Sasuke again before the manga's end"
That "crushing revelation" was made around mid February. So yeah, at the time of chapter 574. Even the dumbest dumbass in the world could have guessed for a family reunion. If he means yet another meeting, then it seems HIGHLY impossible.
"18. Minato is even stronger than what has been shown, you will see why in the future"
Okay now this one coincides with the "Hokage reunion" prediction. It's one of the most genuinely intriguing predictions. But it's still vague as hell.
"19. We will see the clash between Madara and Hashirama, learn more about Mito"
Yet again, a complete given. It's like if I said : Obito will remember Rin and admit he was wrong before he dies. Everyone knows it, no need to have heard it from Kishi to tell.
So, in the end, that guy is most likely a scam. Or at least nothing he said was really so mind blowing he would HAVE to be the one telling the truth. Plus, at the time Tobi = Obito wasn't confirmed. I know if I had any knowledge on how the manga ended and wanted to make it known that I'm the real deal, the first thing I would have revealed would be the true identity of the Big Bad.
PS : I don't care about shipping, but Naruto + Karin would be a 180°/asspull of such magnitude it would make Deidara vs. Sasuke look like the most well written fight in the world.