Yes, when the pedal is floored, it provides maximum power, no matter if ECON is on or off. In both cases Jazz accelerates from 0 to 100 km/h in about 9 seconds or so. I remember trying this once.
I've also noticed that if the engine is already running, the acceleration is more powerful at start. This leads me to believe that the battery alone can not provide maximum power to the electric motor. You get the maximum power once the engine revs up, which takes about 1 second, if the engine is off at start.
Not sure about the cruise control though.