1. Insulation can get damaged, and too much insulation restricts movement.
2. Vader lost against the Galen (clone) you can argue that Vader wasn't trying all you want, fact is Vader LOST.
3. Vader had either superior numbers with him or was dealing with one on ones. Revan faced overwhelming odds without much in the way of backup.
4. You make it sound like he soloed everyone in the temple, he didn't, he was being supported by a clone army.
1. I realize that, but he still had his suit resistant to lighting.
2. That doesn't mean he would lose to Revan, in fact even when he was fighting Galen disinterested he still had a hard time beating him.
3. He probably did on some planets, but he also faced 8 jedi alone on kessel when he was still getting used to his suit and he killed 5 of them. Before the 501st came and killed the rest.
4. I didn't say that, I was just merely saying that he killed more then younglings he also killed the jedi masters and the battlemaster of the whole order.