Driver's side is air supply from the intake tube after the air filter/MAF.
Oil showing up at the grommet on the driver side valve cover may indicate high pressure in the crankcase. I'd start by confirming the grommet is intact. Shouldn't be hard to find a fresh one. Also might want to check the valve cover itself for cracks in that area...
Oil gets into the IC via the PCV - passenger valve cover, rear. Normal, but there are various methods to reduce it.