Meh, this is impossible, since nerve gear blocks input from real body....

It's possible, the 2nd generation hardware doesn't block everything.

no, it has to block it, because the control is still about controlling the virtual body instead of the real body
(remember the way to fly without using the control is controlling imaginary muscles?)
Also when he beats that creepy sugou in the end, he wasn't able to take off his amusphere and experienced all the pain and suffering of kirito's sword
In the end, the Amusphere is only more safe (I guess without the microwaving-the-brain-to-dead part)