Just got done replacing my spark plugs with the NGK Iridiums gapped at about .029 and it's still running horribly. I did notice though that cylinder furthest to the right (4?) had a little bit of oil down where the spark plug screws in as well as some oil on the corresponding spark plug. I also checked the coolant which looked completely normal in color and after letting it run and reach running temperature it didn't overheat whatsoever. As for the smoke, the more I gave it gas the more smoke was released.
I think it's important to note that I just recently had the valve cover gasket replaced about a little over a month ago. I'm not sure if improper installation would cause the oil on the spark plug and where it attaches?