Poe

1) He was summoned by the owner of the house, Roderick Usher, because he is the hosts only true friend. Roderick also claims in the letter that he is falling ill to a disease of the mind.
2) She became more sick and later died.
3) He fears that scientists will want to examine her body because of how strange her disease was.
4) No. His vocabulary is so varied and descriptive that he can emulate emotions. Without his language it lacks voice which creates the emotion of his writing.
6) He makes the house out to be something un-breachable like a prison yet mysterious. The many dark corners of where Roderick is sitting also gives him dark characteristics.
    The host has some problems of his own. He seems to be overall very sensitive about his surroundings and senses. Makes you wonder if something weird is going on with the house itself.
    The eery coincidence that Rodrick's malady dies the night that the narrator arrives does not come off as a coincidence at all. It just adds to the creepy mood.
    He describes the weather specifically the wind which has no influence from humans. The actions of the wind is gusty, violent, and very unpredictable. This gives us an uneasiness because these are strange events.
7) Yes. By only approaching the story with a single emotion there aren't many dynamic opportunities and you can't really vary the emotions portrayed by the characters unless you are going to change the emotion as a whole.
8) I disagree. Edgar Allan Poe is the king of short horror stories and has proven this with his many dark tales. He's so good in fact that we are almost forced to read Poe at least once in our lives. I say that we are forced to because there are very few authors who specialize in horror and keep the gore to minimum while still implementing the same terror.