An interviewer has asked for a copy of an unpublished manuscript I'm writing, is it safe to do this?
There's no concrete, objective answer to this. My opinion is that it's fairly safe to give unpublished manuscripts to an academic interviewer. You definitely need specific permission from all the co-authors on the manuscript, though. If the interviewer is directly in the same field as you, and might be working on the same topic, you might be more hesitant, but it's not a definite "no".  Hopefully, if you're interviewing and considering working with this person, you've already decided that they are not a horrible human being, so you've already done a little of the due diligence.