Our 2014 Crosstrek flashed its low oil level light at about 22k miles. It was due for a change which I usually perform but we decided to take it to the dealer so we could document the issue while it's still in warranty. They have a "program" wherein they gave us a free change and asked us to drive 1200 miles and bring it in at or slightly over that mileage. They will check the oil at that time and calculate an accurate consumption rate. If its over the established limit, I suppose we get a new engine or something. In any case, I urge anyone to get their dealer involved as soon as there is any sign of excessive oil consumption.
Oil filter upside down would not have an impact on the amount of oil on the cylinder walls as this area is not pressure fed. One would have to see a diagram of the oiling circuit to make any judgement on the wisdom or stupidity of oil filter placement. I do agree though, that hearing the engine rattle for the first few seconds after starting is unnerving.
In my (painful) experience, using the wrong lube at assembly can cause the rings not to seat and nothing works better than a teardown to hone the cylinders and replace the rings. Too much lube is detrimental to breakin. There are break in additives available but I would be very careful using them because I have heard they can damage the catalytic converter. Anyway, doing these things to a car under warranty would be very unwise.
