we would all die
The sun would collapse and increase in density. This would increase the rate of nuclear fusion which would try to hold the star apart even harder. At some point other forces like the electron degeneracy pressure would come into play to hold the star apart. If all those forces failed though the sun would become a black hole.
It would be permanently deformed, then break.
there would be no ocean anymore.
there would be no ocean anymore.
The planets would fly off into space and lose their moons and atmospheres. The sun would explode from its enormous interior pressure.
If there was no gravity, the Sun and and the planets would never have formed.
Its own gravity, which is what holds it together now, would probably bring the pieces back together again. It would depend on what caused the Moon to be torn apart. For example, if there were no gravity, the Earth itself would explode. That's because the temperature and pressure of the mantle and the core would blow the crust away. This does not happen BECAUSE the Earth's own gravity keeps it together.
The interior temperature would increase. The rate of fusion would increase. The gas pressure would increase.
the animals would be floating
You used the term nebular. I take it you mean a galaxy. There would not be a balance between gravity and pressure. There would be a balance between gravity and centrifugal force.
Neptune's "surface gravity" is a bit more than Earth's, but Neptune's gravity would not crush you. If you went deep inside Neptune the pressure would probably crush you. That's not gravity crushing you directly, but the pressure. This pressure is caused by the combination of gravity and the planet's resistance to being compressed by gravity. The pressure increases rapidly with depth.
It will never happen because the earth's gravity is caused by it's mass and it's density.