What kind of magic do you like the most?

Are Black/Lava/Arcata dragons already considered summoned?

The description of "hell wave" states: damage to ALL creatures, except demons.

and in general, it's better to focus on dealing 1500 damage than 250 to each.

Unfortunately, neutral magic doesn't scale proportionally with spell power, etc. But if you compare spells at the initial level, neutral spells are stronger than regular ones.

It's pointless to talk about the neutral school because then you would have to include all sorts of skills like "Banshee's Cry" and "Enchanted Arrow."

Why is it pointless? This school exists in the game on equal footing with the other schools. It's just not quite as accessible.