When the Rubies and the Crystal Gems fly to the Moon, Earth is seen in the background. However, the terminator (line between night and day) is drawn from west to east. (North America is shown in daylight and South America is hidden in night.). But in actuality, the terminator should be arranged north to south, between the Arctic and Antarctic regions.
No matter the size of the door, air at one atmosphere being sucked out of any room into a vacuum of zero atmospheres (like space) will always max out at a speed just under Mach 1. However, the escape velocity of the moon is nearly Mach 7; given the way the measurements line up in our universe, there's no physical way Steven would have been pulled out of the moon base fast enough to escape the Moon's orbit.