During SpellCrafting, a Witch will typically ask for help from a diety, and then also use the above mentioned energies to create a positive outcome. WitchCraft is also typically related to Divination. Shamanism is one of the hardest terms to define in this day and age. Another problem we find is that Shamanism is used many times to describe Native Americanism, when in reality it should not be. In general, it is very much like Modern - day Paganism in their beliefs.
Shamanism typically includes animal guides and spirit guides.
In this day and age - not really. Many Witches follow Shamanic practices, whether they know it or not. Many Pagan's would be better called Wiccan's. Many Shaman are actually Witches. Just remember, if your would like to be real picky, it may take years to study the ancient definitions and train yourself to the letter.