we can fly
The same thing that happens every night when the sun disappears...nothing! Gravity on Earth is not dependent on the Sun. But life on Earth is, gravity would be the least of Earth's problems if the Sun dissapeared
In that case, the Moon would move in a straight line instead of moving around the Earth; it would quickly get away.
If the force of gravity on Earth suddenly grew stronger, your weight would increase because weight is a measure of the force of gravity acting on your mass. Your body would feel heavier and you would find it more difficult to move around.
What would happen to the earth if the sun's mass (and, thereby, its gravity) suddenly went to zero? The earth would continue moving in the direction it was going when the sun's gravity disappeared. It would depart the area on a tangent to its original orbit and head off into space. There would be dark days ahead.
The earth's water would evaporate.
It will never happen because the earth's gravity is caused by it's mass and it's density.
Your mass would be unaffected, it is simply to do with the atoms in your body. Your weight would be reduced to zero as that is simply how much your body is affected by gravity.
If gravity suddenly disappeared, the moon would fly out into space in a straight line. If the moon suddenly stopped moving it would fall straight into Earth.
If gravity suddenly did not exist on Earth, everything would float off into space since there would be no force holding things down. The atmosphere would disperse, water bodies would break apart and life as we know it would not survive without the gravitational pull that keeps everything in place.
we would die
There would be less gravity on earth.
It won't; a moving object has the object to continue moving. If one day the Moon mysteriously and suddenly stopped moving around Earth, it would fall upon the Earth pretty soon (in a few days), due to Earth's gravity.