Short question:
Does Lightning Bolt/Ball Lightning cause Physical damage or Stun damage?
Long question:
SR4A, p. 163, Electricity Damage. This section implies that all electrical damage is treated as Stun damage. On page 164, it clearly states, "Electrical damage is treated as Stun damage and resisted..."
SR4A, p. 204, Damage Value. "Each spell description notes whether damage is Stun (S) or Physical (P)."
SR4A, p. 205, Lightning Bolt (Indirect, Elemental). The spells are clearly listed as causing Physical (P) damage.
I'm inclined to believe that the spell form causes physical damage, but I'm open to interpretation.
Next question. How does this relate to critter powers such as Elemental Attack and Energy Aura with electricity?