I am not an expert on your particular engine, but I am familiar with valve stems seals, having had the problem on a water cooled VW years ago.
Worn valve stem seals will cause oil consumption. The start up will result in a white/blue smoke. It has a distinctive pungent smell and lingers. Surely you have been stuck behind a car that is a "Mesquite Fogger" and have rolled up the windows to minimize the acrid smell? With worn valve stem seals, after warm up, the emission of blue smoke stops, although the worn seals will continue to leak oil into the combustion chamber and cause mild oil consumption. The amount is small enough that it is not visible in the exhaust after warm up. You may see some slight wet blackness on your spark plugs. A light tan color is the desired condition.
I believe you are seeing one of the by products of combustion, H2O. Any internal combustion engine produces H20. A cold exhaust system causes this water vapor to condense in the muffler. As it continues to warm up, the hot gases cause the condensed water to turn back to steam. Eventually the whole system gets hot enough, that the water is purged and the vapor content low enough that it is no longer visible. It is not unsusal for a cold car to actually drip water out the tail pipe.
Sounds like your car is fine. If you have any doubts, let some one else start the car and you can stay in the back and smell the exhaust! Just don't breathe it too long, it's addictive!
I will come out and smell the exhaust for a small fee if you are still unsure