A web app should have direct access to an OpenGL.
No it shouldn't. I don't want to go to a web site and have all sorts of flying 3D shite on my screen. Flash is bad enough in this department.
HTML5 can play audio (usually poorly) but there is no API for recording it.
No there shouldn't be. I don't want to go to a web site and worry if it is recording me or not. Hello FBI, CIA, NSA, Facebook, Google, etc. - sod you with a stiff wire brush.
There should be a way to interface with cameras, etc.
No there shouldn't. I don't want to go to a web site and have the fumbducktards at the other end spying on me - see above.