vertex normal directions

After smoothing, I have inappropriate shadow and light edges where there are multiple veritxes touching.

If I weld those vertexes to one, the shadow and light edges go away --beautiful.

Problem is welding is too destructive. Ie one loses vertexes and thus can't just move those faces around separately anymore. What if I don't like the change (after more testing)? The only way I know to undo that (once file is closed and reopened) is to duplicate the faces of those welded vertexes, move those new faces out, then delete the original faces and move the new duplicates back to orig position.

So...

Is there a way to get rid of those light/shadow edges without actually welding vertexes? Ie is there a way to make vertex normals perform as welded without actually being welded?

"Rotate normals" (under tools panel/ mesh) might be a way to do something like that. But it doesn't look too easy (and I don't know how).

So my question of this post is how do I make the vertex normal directions act like they have been welded?

-Use "rotate normals"? (how-to please)
-Another easier way?

Or is there a way to create two vertexes from one (thus undoing a weld)? (I don't think so.)

If so that could be a neat new feature.

-------
Thanks for the prog.

Spellir