Questions about the story of Joseph.

The story of Joseph has always been a "Mystery wrapped in an enigma". To put it bluntly the story makes very little sense. The commentators' modern and ancient have struggled to answer these few fundamental questions:

1. Why doesn't Joseph send a message to his father after he becomes king of Egypt?

2. Joseph left home when he was seventeen. How is it that his brothers do not recognize him? the Midrash answer "that he grew a beard" seems a little nonsensical. This question becomes even harder when you consider that in all likelihood all of Egypt knew the story of the boy slave turned king. How did the brothers not hear it?

3. The "proof" that Joseph asks his brothers to show that they are not spies, is just pointless and seems to have no internal logic. There really isn't any proof that the brothers are not spies just because they "were born of one father". Having another brother, is certainly no better proof. It is unclear what having another brother proves, nor what is to stop the brothers bringing some other child and claiming that he is Benjamin?

4. Even given that the brothers did not recognize Joseph when they first met him, Joseph seems to throw so many clues their way that it is a further mystery that they did not pick up on it. Joseph:

•  Uses phrases particular to their family, such as mentioning God, The Gods of their fathers etc..
• Punishes Shimon above the rest of them (traditionally the Midrash explains that Shimon was chosen as he was the one who threw Joseph into the pit.)
•  Seats the brothers in the correct order of their birth.
• Clearly shows that he is not Egyptian since Egyptians will not eat bread with him.  
•  Asks them to bring Benjamin with them.
• Joseph singles out and honors Benjamin above the other brothers by giving him 5 fold servings of food and later riches.

I've searched and searched but have not found any convincing answers, certainly not one that answers all the questions. In the next week I'll try and review some of the answers the commentators have given, but I am interested to hear if anyone has original answers to these questions.