The part of Hegai, the Royal Eunuch is played by Tommy 'Tiny' Lister, who has a deep, resonant, basso-profundo voice. Hegai says the same sword that cut his eye in battle took his "manhood." A man castrated as an adult is technically a 'eunuch' and could have such a deep voice. However, eunuchs were more often castrated on purpose before puberty resulting in a higher pitch.
When Esther is running to see the king to plead for the Jews the scene switches back and forth between Xerxes, indoors, and Esther, outdoors. Esther is running through pouring rain yet when Xerxes is shown sunlight can be seen shinning through the windows onto the floor and across the faces of those in the room.
When Esther is in the courtyard of the harem eating she throws food to a monkey. When the camera shows Esther tossing the food it is obviously a thin sliver of meat, however when it cuts to the monkey picking up food it is a banana, or some soft white/yellow fruit. These shots are shown twice.