As to differences between spear and pole work- pretty simple- how you apply force will be a bit different. As an escrima guy, I get ****ed when people tell me the stick is a representation of a blade. Training as if the stick is a blade tends to lead to weak, wrist powered hits which depend on an imagined edge. Train as if the stick is a stick; learn to deliver power with it; then train with the stick as if it's a blade- focusing the power on an imagined edge. This being kept in mind, a spear is generally gonna be used against people in armor, so you'll cultivate a sharp force to penetrate with, then drive in, essentially trying to hammer the point in - a common technique in western martial arts. Check <http://www.schlachtschule.org/> for some examples.