I always thought about the relation. Thunderbolt... the sound of the attack and, Lightning...... the flash of the attack. I',m sure the two names had nothing to do with each other.
And as much as i love the Lightning as an air superiority fighter as far as i know the Lightning was a disapointment in Europe. As an attack plane that was different. It was one of the most versatile as i know.
In the Pacific of course it was a complete monster. And ate Jap planes for breakfast. Due to it's huge speed difference, climbing ability, decent maneaverability, amazing firepower that would rip Jap planes in half with one burst, and teamwork, it was one of the reasons Japan lost. The Germans had planes that were much more of a match however.