Let's suppose we could dump enough "breathable" air (whatever that means for humans) into the solar system that it filled the spaces between planets.

What would happen?

A - I imagine it would then become possible to fly airplanes between planets, perhaps balloons? Would space travel become easier or harder?

B - According to another lemmy post, we would start to hear sound waves from the sun (A constant jackhammer sound - delightful)

C - Each each planet become the center of some mega cyclone (like the Jupiter storms, but bigger)?

D - At some point the air above us wouldn't be pushing down onto the earth at sea level, could we survive the additional pressure?