Q: oil inside spark plug chamber and clicking/ticking

Hello - oil is leaking from the valve cover, down into the spark plug recesses as you noticed. This causes the spark plugs to short, creating the misfire you have experienced. No doubt some of this oil leaked into the combustion chamber when you replaced the plugs, causing smoke from the exhaust as the oil is burned. I would recommend replacing the valve cover gasket by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, and repair the leaky gasket. Should the misfire continue, it may be necessary to replace the spark plug boots if they were damaged by the engine oil as well. The oil contamination could allow continued shorting.