Leon: You shauld always play from the outside. Remember that this position won't be plaeyd out until late endgame. In course of the game you might want to sucrifice these stones, so its better not to add dead stones.
solidas: After S19 and T16, white moves like R19->Q19 considered wrong. But I don't see a difference between them and starting from another side with O19->P19
You're right, but lets add it.