Dumb question (spoilers)

What was the point of killing them all? Maybe Michael survived, I don't think it showed him being killed?

It was hard to understand their accents, but did it possibly have to do with what they were talking about in the beginning of the movie (when the blond girl was "passed out" on the bed)? Were they in some sex industry?

I dunno. The movie was somewhat entertaining, I thought the ending was ok, but the acting was eh. I felt like they were shouting the whole time...and the camera scenes that were going up and down the stairs drove me crazy.

Lastly, the blond girl was stupid. Why on earth would she go back to the house...she could have made it.