Not exactly. Acid rain does contain abnormally high amounts of nitric acid and sulfuric acid, but the concentrations are still very dilute.
No. Muriatic acid is hydrochloric acid.
Sulfuric acid is more stronger than Nitric acid, but Nitric acid is more reactive than Sulfuric acid.
Sulfuric acid = H2SO4 Nitric acid = HNO3
Nitric acid = Aqua Fortis, Spirit of Nitre Sulfuric acid = Oil of Vitriol, or simply Vitriol