I think you're completly wrong with last point.
There already exists a lot of challenger, like litecoin, but they are 10km behind.
Moreover bitcoin have taken 5 years to emerge from nothing and it is now the first.
If a real challenger must be born and grown up, it must have several better features than bitcoin.
And even if it is possible, it will take at least 2 or 3 years to get to the first place.
Being the first is a great advantage : see microsoft, amazon, facebook, tweeter, etc...
Yes Google have beaten altavista and yahoo, but it had new concepts with true better features.