Weight and gravitational pull of the planet?

If the planet's atmosphere was filled with different gases and not oxygen, could it's weight and how it sits in the universe be lighter or heavier, causing it's gravitational pull to be sucked into a different position?  Will continuing to remove massive amounts of heavy oil from the ground and turning it into a weightless gas make the weight of the planet lighter, ultimately making it possible to change course in the galaxy, moving us closer to Mars and the sun?

Questions to Science

What effect does nuclear weapons that are released into the atmosphere have on the planet's ozone layer?

If you mix oxygen with a toxic element in a bubble, can one over power the other making it non-existent?

If less and less oxygen were to happen slowly on this planet, would the clouds get lower, essentially having the "sky is falling" effect?

Why are hurricanes stronger now and more numerous than they have been in the past 30 years?

Considering the theory of evolution, could we eventually evolve into bald green beings with black eyes that can see in the dark if we polluted planet so badly that it blocked the sun out and caused fungus to thrive?

Do cars or trees breathe faster?

I have a hard time believing that the number of planes, trains, and automobiles is good for the oxygen levels on our planet.  I look at mars and think earth could become that way if we continue to change the chemical composition of the elements in our atmosphere. Are we creating our own doom?  The three most basic needs of survival seem at risk....air, water, and food.  When I sit at my country home and smell auto fumes with no running cars around, I feel concern.  There has to be a better way.