Ok listen, if the turbo seals are bad it will constanly smoke. If the smoke subsides at idle, and you can drive the car around normally without any smoke and when you build high boost and then let off and it smokes its the pcv diaphram in the INTAKE MANIFOLD. has nothing to do with the valve cover. There are 2 things that will cause high crankcase pressure, 1 like i said a boost leak of the pcv in the manifold, 2 a broken compression ring. Do a compression test, you should have between 180 and 205 psi cranking. If all cylinders are in that range its the pcv in the manifold. As far as the miss at idle, you have a bad plug, or wire, or coil. If it really sucked in a lot of oil it may have fouled the new plugs you put in. It takes a while for the oil to stop. And gap them at no more than .022