I think basically "most" people with DP are usually, to be blunt, fucked up. It's simply true. It's usually a symptom masking other mental/emotional symptoms. In that sense, it could very well be dangerous (and I'm not talking about the "your father might be schizophrenic, have a psychotic episode, and kill you dangerous"). But, and I can almost guarentee, my father experienced dissociative symptoms, as well as DP/DR. I never knew about it. What I did know about was his temper, his rage, his demands, etc. Was that dangerous to me? Oh yeah. I don't know your father at all, but he's probably got some buried issues there, be it depression or anxiety, anger or inferiority, and what not, and this could very well be dangerous to the people around him (children especially), either in what he IS doing or what he's lacking as a father.
But that's just assuming his DP is the result of other issues. Again, usually DP seems to be the bottom of the barrel, IE dissociation from a severely troubled psychological/emotional state. We aren't healthy individuals!