I would recommend that you leave the oil for the recommended period. However like you I don't like the idea of leaving the factory fill in for 10,000km or what ever they recommended.
With my last new car (wifes renault clio) the oil was never changed at the 1500km check and not intended by the agent to change till 10,000km. So at 5000km I could not stand the thought of the original oil and any new machining swarf running around. So I changed the oil and filter using basic mobil super mineral. At 10,000km the agent changed as specified to Mobil super S (semi synth).
With all new cars that I have had over the past few years of have refrained from full synthetic oil till 30,000km. I mean by that time the engine is well and truley bedded in and worn to correct tolerance, only till around then is it worth putting something in that attempts to slow further wear.
I have heard of problems of putting full synthetic in to early as the rings never bed in. Recently I heard of the citreon agent who
had been putting full synthetic in at the 10,000km service, by 20,000km they were re-ringing them, they tried to pin the fault on the factory who quitely pointed out that the local pug agent had no problems, same engines off the same production line, only difference the pugs only got mineral or semi synth in early life.