The series does not cover this far.
We don't know. Most likely Gryffindor but she is mentioned to be smart so possibly Ravenclaw.
Ron weasleys father and molly weasleys wife.
no i dont think so
The Hogwarts house ghosts are...Nearly headless nick (griffindoor)The grey lady (ravenclaw)The fat friar (hufflepuff)The bloody baron (Slytherin)