Headscratchers / The Mummy (1932)

• How did Imhotep regenerated himself?
  • Perhaps by reading the scroll gradually in order to resurrect him completely?
  • But he have undead features, as a dirt touch hand print. And dry skin. Well, I really don't know.
• Why Imhotep didn't kill Müller and hypnotize Sir Joseph Whemple in the house to give him the scroll? The dude can kill anyone with some magic words literally. Most, why he didn't kill Müller? He is an scholar with great knowledge about supernatural beings and practically the most dangerous menace to Imhotep, despite being a extremely powerful undead.
• If Imhotep had the ring and his arcane magic knowledge as a High Priest, why he didn't kill the guards that arrested him?
  • It's implied that as part of the curse, Imhotep became a immortal being, mostly a lich as a resurrected mummy. He and the characters know that he is invulnerable to everything, he breaks easily metal bars offscreen, and uses spells and powers of evil gods to kill with spells. Without pass to the afterlife, cursed and immortal, he uses the powers and the favor of dark gods. Even Müller and Joseph Whemple refers him mostly as a being.