You mean the poison that he needed Shilliew to save him from, right? He didn't just tank the poison, it almost killed him, and would have were it not for Shilliew coming to his aid.
Vari = volts - check
http://onepiece.wikia.com/wiki/Goro_Goro_no_Mi. Vari is a translator's version. In the same way you get Zolo/Zoro. You still haven't answered my point about him waiting until Whitebeard was close to death, then using his crew and a load of guns to finish him off. If he's as strong as you seem to think, why didn't he just attack Whitebeard before Marineford, or even fight him singlehandedly? And why didn't he attack the admirals, or Marco, or Jozu, or any of the other Devil Fruit users that were around? He came in when WB was severly injured, already dying due to his age, then getting stabbed, shot with lasers, and fighting off a lot of marines. He then shot him (with his crew), stole his powers, and ran. He's not immortal, nor is he omnipotent. Kurouzo does not equal an instant win against people.
I'm not saying Thor gives Enel an instant win, either, I'm saying that in a match-up of slow, brute force, hand-to-hand fighter vs potentially long-range, speedy fighter who's powers seem to excel at keeping him at range (Mantra, for instance, to avoid BB trying to grab him) then the fight is likely to go to the guy who's powers are more advantageous. Enel would still lose to WB, to Rayleigh, potentially to Akianu. But against BB he's got a great match-up.