Iconography in Buddhism - from the Greeks? And why isn't the Buddha bald?

When you read or hear about Gotama leaving his home and family, the story is usually something like "he shaved his face and head and went out to be a wandering monk". But very few depictions of the Buddha (perhaps apart from the laughing, fat buddha) is of a bald man. Why is that? I've also heard, but don't remember the source, that in early times there was no iconography in Buddhism. As far as I remember hearing, depictions of the Buddha did not appear for many hundreds of years. Actually I've heard that the iconography of Buddhism actually comes from the Greek,,that the first to make icons of the Buddha were Greeks living in India. There's obviously a lot of variations over time and between traditions. But can anyone give me some information, and sources about Greek influences on Buddhist iconography? Also I wonder why Buddha almost always is depicted with hair?