When Luke fell...

Before he jumped he had a good look down . If he didnt use the force then he must be a very lucky boy

Too lucky I would say.

He expected to die, which to him was the preferable option rather than joining Vader. Either luck or the Force allowed him to live.

Or both.

Maybe Vader used the force to keep him from smacking in the floor....

Sure.......

Nah...

He chopped his hand off

Exactly.

The vents are very big so it was easy lolz

True, and maybe they had some strong suction at the bottom as well..

I doubt Luke knew that.

He didn't.

Nah.

Obi Wan fell some good 30 meters in Episode 1 landing on his shoulder.
Anakin fell some >1000 meters landing on a speeder in Episode 2.
Yoda fell from the senate pod to the "middle pod" landing on his back.
From there he fell down to ground falling on his head and doing some sommersaults.

So I dont really think it would have mattered what was down there. Star Wars universe works with physics of the original Doom, You just cant die from falling.

Those laws of physics mellowed by the time of the OT, since they relied on the Light Side to work.

Physics??? This is SW peeps...

What 30 meters was that in EpI?

http://img207.imageshack.us/img207/6227/fallyk7.png

More like 10 meters on a second thought but not a bit less leathal.

It is less lethal for a Jedi.