7- Why has no one called for the Doctor's help?
You should know better. When shit happens and the deux ex known as the Doctor needs to be taken out of the picture, they simply leave him out. Plus, there is no tech to call him. To my knowledge, Jack doesn't have anything to call the Doc with. (...and yet 1940's Churchill can....)
Plus, Gwen kind of explained it in COE: she said something about how she thought that the reason the Doc didnt come sometimes and sometimes he did, was that he would turn away in shame of humans. COE was caused by humans themselves. MD is a human act as well. There is obviously some alien in there too, but it seems it all began with the Triangle and they were human. Or so they seemed.