Revenant Spetres + quality Spell echo?

I am linking spell echo in my revenant spectres, has I understand they don't cast spell, only att with projectiles.

http://pathofexile.gamepedia.com/Spell_Echo

1st: Spell echo only helps in the cast time (the animation) of the normal att?
2nd: does quality in the spell echo gem improves the dps of the revenants in any way? (quality improves the spell damage)

Thanks ahead
Regards

1. They are casting a spell, otherwise echo wouldn't work.

2. Spell damage works too, it's a spell.

so it's a spell with projectile damage? like ball lightning?

Yes, a lightning projectile spell, like BL or Spark.