Naruto Chapter 434

[Abdula]

Where did you get this from?

Its right in Poopdeville's link

http://www.onemanga.com/Naruto/410/15/

Not rly. It's usually more like a force push, like seen here

The only time it took the form of a sphere was when he took out the village

Here when he is defending against Kakashi raikiri's, its in the form of a sphere and it even destroys the wall behind him. I think it happens again sometime after that too when he gets attacked by multiple opponents.
http://www.onemanga.com/Naruto/420/10/
http://www.onemanga.com/Naruto/421/13/

[Archangel]

Its right in Poopdeville's link

I meant why do you assume he's already absorbed all of his sage and normal chakra?

I don't think he would be dumb enough to even try to suck the slightest amount of his normal chakra since that's just begging for the kyuubi to come out and wreak havoc