A 300-hour yoga teacher training is a great way to increase your knowledge base and refine your teaching tools. It builds on the knowledge from the 200-hour certification, and adds greater detail into every limb of the practice.
There is no doubt, with Hatha Yoga and its explosion in popularity in the west, that physical poses (asanas) have become very prominent. Yes, it is a great feeling to touch your toes, balance on your hands etc. But what is the point?