I'm not into stage singing since I never got serious about the band thing.
But a professional singer from a metal band where I grew up said that he sung from the gut.
That the stomach has fewer muscles to strain the body through a set.
I could'nt really say otherwise since he was a stage singer and I was'nt.
I would think that that gut method would put more strain on the body because of the fewer muscles to absorb the strain.

I would like singing anything from Radar Love, Roxy Music, to Nirvana songs.
And the only way I could sing them is out of my chest.
I could'nt make the sound another way.
Of course Ozzy is more of a nasal singer.
Nasal singers I notice have that falsetto voice.
I sound like a wacky chipmunk character when I try to sing nasal. All I can do is push up from my chest to my throat.
I was tested at a 5 octave range, yet I could never keep my voice above 3 for too long. Even when I practiced.
There are singing methods I would'nt mind checking out.
Every little bit helps.

Matt

http://www.f3music.com/444