I recently started playing Shadowyun (3rd edition) and I've run into a few problems with regards to grenades and explosions. Hopefully someone here will be able to help me out. I realize that the answer to some of these questions may be "RTFM", but if so I'd appreciate a "RTFM page XX" answer.

I'm sorry if some of these questions are hard to understand. I'm hoping to avoid detailed descriptions and examples. Let me know if I can't.

1. Is there a way to have grenades explode on impact?
2. How do the barrier rules handle stun damage? Same as regular damage? (Commonly comes up with concussion grenades.)
3. Are there specific examples of the Barrier Ratings of walls and doors somewhere? The Barrier Rating Table on page 124 uses generic terms like "Average Material" and "Hardened Material" and I have no idea what that means in-game. What is the barrier rating of a typical door (inside an office or house)? A wall? The floor? A solid front door?
4. Which barriers "count" when determining a blast's power in a specific spot. I assume the floor/ground doesn't count - what about the ceiling? Does an explosion do less damage to airborne targets?
5. Any rules-of-thumb for determining the added power from a "diagonal" rebound in a confined space? (If you understand what I mean by that.)
6. Am I right in assuming that the power of a blast in a confined space keeps building until a barrier breaks or the explosion runs out of juice? So, if a barrier holds on the "first attempt" the blast will rebound and possibly return from another barrier to "try again" with more power? Do you lower the barrier rating after each rebound?
That's it for now, I'm sure I'll have more questions later.