Is the fate of the sisters just?

Yes, the fate of the sisters is just. Everything they did to Psyche was out of jealousy because she had a better life then they did, according to them. In the beginning of the story they found out that Psyche lived in a magnificent house and had a nice husband. They saw all the jewelry she had and they wanted it. They also told Psyche that her husband was an evil monster and wanted to eat her. So they told her to kill her husband while he was sleeping. They did this because they didn't want her to have a better life than them. " Tunc nefariae mulieres puellae cogitationes invadunt: 'viam quae sola ducit ad salutem diu goitatam monstrabimus tibi"(li 23-24). In the end Psyche lied to them and told each one of her sisters that the man she was going to kill was Cupid himself and he left her and wanted to marry one of the sisters. When the sisters heard this they went to Cupids house in a heartbeat without thinking about how Psyche felt. Since Psyche tricked them they jumped off the cliff and were killed. 

List and discuss the specific instances of fear. Whats the opposite of fear?

Fear shows up alot during the story of Psyche and Cupid. From the beginnning when Psyche's father finds out that she will marry a hideous beast up untill Psyche thinks that a serpent like monster is sleeping with her during the night. Some specific examples of fear during the first 8 chapters would be when Psyche laid in bed and she heard her unknown husband come into the room. Since she could not see him because it was dark she was, "virginitati suae metuens et pavet et horrescit" (li 23-24). Another example of fear in the reading is when Psyche's sisters persuaded her to believe that her husband was a monster who wanted to eat her and her baby. Once she heard this, " Tunc Psyche misella rapitur verborum tam tristium formidine..."
( li 16).
The opposite of fear would be calm, welcomed and love. When Psyche was first brought down to her new home she was completely calm. Psyche, "In toro roscidi graminis suaviter recubans dulciter conquievit"(li 1).
She then went into the beautiful palace that was made "Non humanis manibus"(li 4). She was completely calm and she felt very welcomed when she entered the palace. Througout her time in her new home she was full of calmness and love, there was no fear in her at all.

What elements of Appuleius' story so far are "classical fairy tale" characteristics?

The fairy tale Cupid and Psyche can relate to the disney fairy tale Beauty and the Beast because they share the same "classical fairy tale" characteristics. In Cupid and Psyche, Psyche is so beautiful that no one wants to marry her and her father goes to the oracle to find her a husband. When the oracle tells him that she will be married to a hideous creature he hesitates but listens to the oracle. He has to place her on a cliff edge and when he does that a calm wind takes her and brings her to a very serine place. When Psyche gets there she is greeted by voices that don't have any bodies. These voices wait on her hand and foot and they make sure she's ok. This relates to Beauty and the Beast beacues when Belle gets to the castle she is also greeted by strange noises. At first they don't show who they are to her but later on they show that they are the furniture that are all located in the castle. Just like Psyche the voices try to help Belle as much as they can. In chapter 3 of Cupid and Psyche it introduces the voices to you. In lines 10 through 14 the voices tell her that they are her servants and will take care of her. They are going to prepare a feast for her that is "regales dapes". In Belle's story the voices also make her a feast fit for a king. There are all sorts of kinds of foods they make her just like the voices did for Psyche. This shows how elements from Appuleius story are used for fairy tales today.