Moses and Exodus 10

At first, Moses did not want to return to Egypt when God called to him from the burning bush. Why was he so resistant? Why did Moses want to know God's "Name?" God promised to provide Moses with a "sign" which would assure Moses that God was with Him in Egypt. What was that sign? And when God told Moses to ask Pharaoh for a three-day cessation from work so the Israelites could go and worship God, why did He not instruct Moses to demand their permanent release instead?