Chakra isn't what completely knocks away the incoming attacks. It's Neji's spinning which allows the released chakra to deflect them. I doubt Neji's chakra control and power is so great that he could just deflect tons of shuriken just by releasing it. If it is, then it wouldn't make sense for him to spin as he can just stand there and release chakra all day.
Yes...and? My point is still the same. Even if Sasuke can see Neji spinning in slow motion, it doesn't mean Neji's actually moving slower. He's still spinning fast and releasing the Chakra using a normal Kaiten.

Come on, a lot of this shit is hypothetical but we have to assume that Sasuke is at the very least, as strong as Naruto is (and we all know that he's da most powerful).
I agree, but we unless we know exactly how much he's improved, and what he's capable of, we can't use him in this argument.

As for your sharingan comment, you basically just reworded what I said. I agree, Sasuke's speed > Neji's speed.