Not sure on the coils - they do fail - but I can tell you my 03X has been burning oil, not quite at that rate - maybe qt/500 miles on bad cycles, for going on 100K miles. It's done it since i bought it at around 120K. I've since had the HG replaced for a minor external leak, along with full valve job, timing belt, etc, and it really didn't change the consumption much. Still been consuming oil, still been going strong - no leaks or noticeable smoking.
That's not to claim yours will be OK - still pretty alarming - was for me at first - but just relaying my experience with the same engine.