Does an elevated Black Panther have line of sight if his sight first crosses hindering terrain, a blank square, and then a character with stealth?

Yep. An elevated Character ignores all intervening terrain features(except for blocking terrain).

Hope this helps...

As long as the stealthed character isn't standing on hindering terrain. You ignore all hindering terrain when drawing LOF except for the square the figure is standing on.

Now here's the REALLY cool thing...

That same opponent cannot see Black Panther because of that very same hindering terrain between them! AWESOME!

Since Black Panther is on elevated terrain then the character on the ground can see him (since Black Panther is on an elevation that is different than the hindering terrain).

Not quite. Black Panther looking down ignores hindering terrain unless it is in the target's square. Batman looking up must deal with all intervening hindering. Black Panther can Outwit Batman, but Batman cannot Outwit Black Panther.

Just for clarification.. if Batman is on the ground and IN hindering terrain he has LOS to Panther at the edge of elevated correct?

That is correct flaxwless