nethog, I think the answers to both your questions are in the rule book, but to make it easier, here's what it boils down to:
1: When a hero is knocked out, his figure is removed from the board and replaced by a hero token. This means he is NOT on the tomb when the light hits it, unless he's been revived, at which point the token is removed and replaced by the figure. When you're knocked out, your hero is off the map and can't be targetted except by specific actions like revive, or some quest specific actions, like stealing locks of hair.
2: Walls and full red lines block what I call "line of effect". You have to count around them. Some terrain effects like elevation (red hash marks) or bushes (green door-like things) block line of sight but not your line of effect, meaning a target can be affected, if you don't require line of sight.
Edited by Alarmed, 07 August 2014 - 10:48 AM.