Wasn't the original scene between them supposed to have Anakin actually FALL into the lava and Obi Wan, to show the light side of the force, actually raised him up? I think that's how it was supposed to originally play out. Am I right?

No.

The way it is supposed to be played it ended up on screen. Why would you think otherwise?

I don't know but it would seem to actually be a worse thing to pull his body out of the lava to die a relatively slow death than to let him die quickly in the lava so I doubt this was the plan.

I read once that he was supposed to fall. I will try to find the text.

Wouldn't one die pretty much instantly submerged in lava?

I read it a long time ago before the prequels were even being planned and the sequence in the movie is exactly how it was written.

Darth Vapor

It was mentioned that Anakin fell into a pool of lava in the ROTJ novel...but that is about it...the same book also said Owen Lars was Obi-Wans brother...but that went out the window too.

Here we go...and exclusive look at the original Anakin/Obi Wan scene...

I will find a source for this tomorrow. I know where to look and I will copy/paste the text when I find it.