Because this is free for anyone with a iDevice, and it can use the inbuilt mic if needed.. I do however agree on not plugging anything potentially high voltage into my iPhone.. !
(Killed a iPod Classic 160gig by applying 15v to the outer case… )
Nope, not possible (since its not a official apple approved thing).. :(
(Can’t even use the camera connection kit with a iPhone, you have to have the iPad .)