Nope. It gives the body/brain the O2 it needs to survive for a while, but CO2 will still build up, leading to:

http://en.wikipedia.org/wiki/Respiratory_acidosis

Probably. So a life-saving measure in extreme circumstances, but certainly not something you can use indefinitely.

It seems like that might be eventually possible, but for now the technology is limited to a few minutes - like until an airway passage could be cleared.

"It could sustain patients between 15 and 30 minutes after experiencing respiratory failure."