To soak up the excess blood. Exactly the same reason why butcher shops use to have their floors saw-dust coated.
Vampires turn to dust in the light. That is why they sleep in coffins.
Near a dead vampire
yes
yes dust mites can get anywhere dust can get.
Once a week or they turn to dust
No, you do not. You can only become a vampire by being bitten by one, either contracting Porphyric Haemophilia from vampire enemies, or by allowing Vicente Valtieri to turn you into one.
Such storms where so strong it could cause death on human people.
The Dust Bowl was the result of a lack of soil conservation measures; so the answer would be: none.
Sun plus. Vampire
The process of making a mummy required the removal of vital organs, stuffing the body with dried herbs and other things, letting it dry and then wrapping it. It was placed in a coffin within a coffin. All of this preserves the body and makes it last longer through time. The process of mummification involves drying the body so mold and bacteria will not cause it to decompose. That is whey Egyptian mummies last in their coffins and do not turn to dust.
After the guy has come running to you and you complete the quest by slaying the vampire you should learn that he lives in the imperial city.
This comes in under the maybe category. Burning the body is considered a sure way to destroy a vampire, however if a vampire were to become dust by some alternate means then perhaps reconstitution is possible. Count Dracula was able to transmogrify himself into many thing and then return to his true form. One of his transformation was to a green mist, and if he could do that then surely he could do as much with dust. It should be noted that, besides being a vampire, Dracula was also a high order sorcerer and his ability to do extraordinary things probably has nothing to do with his being a vampire. Perhaps here it would be worthy to note that when Dr. Van Helsing's band cornered Count Dracula outside his castle near sun-set, when the Count's powers were at a minimum, when he was stabbed in the heart he turned into dust and blew away on the wind. This is usually considered the end of The Count, that because this occurred during the day this was not a means of escape but his end -- but then you never know.