The 4 O-rings that seal the valve cover to the head are likely the cause of oil collecting in the spark plug well, but that shouldn't be the cause of losing 3 qts of oil. Those O-rings are included in any valve cover gasket kit.
Are there heavy traces of oily carbon deposit on the tailpipe or on the rear bumper cover?
I've read that the 2.5 had issues with the oil baffles that are located on the underside of the valve covers. They can get gummed up over time blocking the oil passages, then the oil then finds its way through the pcv system and gets burned out the exhaust. I haven't read of that same issue on the 2.0, but it does share a similar baffle on its valve cover. I would start by pulling the valve cover for a good cleaning and replace the gasket and O-rings. That might fix both problems.