Not only is there no air, but there is no air pressure in space. I human body is pressurised, and sufficiently so it will push out against the normal air pressures on earth. To put it another way it's like lots of little hands are pushing out from inside the body, knowing that lots of little hands will be pushing back from outside the body with the same force, ie air pressure. So when a person goes out the space hatch into an unpressurised void those little hand pushing out just keep on pushiing out. There are no little hands pushing back form the outside. The result of this is that the person very quickly explodes. Not a pretty sight but faster than suffoction.
As there is no air there is nothing for the suns rays to hit an warm - space is cold, far colder than the North or South pole. Fairly soon after leaving the spaceship hatch a person would be frozen to death - had they not already exploded.
Again this stems from the fact that there in no air in space. No air means noise can not be conducted ie no noise from those explosions.
The explosions them selves I'm not so sure about. No air in space means there is no combusion as fire needs air to survive. Just try an experiment where you deprive a flame of air and see how long it lasts.
The tradditional experiment for this is to secure a candel to a plate whith a little melted wax. Fill the plate with water and place a glass over the light candel. The water prevent any fresh oxygen getting into the glass, as the flame uses the oxygen in the glass it snuffs itself out.
However a lot of the things shot at in the movies would have air in them and so to the extent that the air feed the flame there would be some flames to the explosion, I just have an unscientific hunch that the movies over dramatise this and in reality and explosion would never be as big as they make them. But hey who complains when they are watching the explosion of the DeathStar