We do know from that 2009 statement from deputy af chief that j20 is intendent to feature 4 s, supercruise, stealth, short take off and sopermaneuverability. Perhaps current engines can't quite cut it but once ws20 gets used it will be another matter.
Actually, J-20 has lower aspect-ratio (narrower) than Flanker. That means given the same thrust, J-20 experiences lower supersonic drag. A low supercruise speed is well in the realm of possibility.Unlikely super cruise with old Russian engine.
I beg your pardon, did you mean nose hidden?Why noise hidden ?