Keywords - when should the parent keyword be chosen

I have constructed a keyword list for personal photos.  My diese question concerns surnames.  None of the choices for hierarchical preferences are currently checked (automatic, write, read).  I have people associated with surname groups so some of the people do not have the surname, for instance a man who married a woman with the surname.  If the surname is Jones, and I have a person named Samantha Jones Rogers, I just tick her name, not the parent keyword "Jones".  She would come up in the search for "Jones" as I have retained the maiden names for all married women.  Is there something I am missing here?

Another consideration:  if I were to switch to Lightroom, how would my choices now impact how a search would work?  Should I change the read, write preferences?  I am not exactly sure what they are and how they impact searching in general.

Another related question concerns place names.  So if I have a state, say Massachusetts, with cities and town under it in the hierarchy, I would have to check the parent Massachusetts in each case as the city is just Boston.  If I wanted to pull up all photos of places in Massachusetts, that is the only way it would come up since I don't have the automatic setting on.

Considering both of these issues:  I understand that brackets can be used if the parent keyword should not be automatically included.  Would it be best to turn on automatic parent keywords but put the surname parents in brackets?  That way I would not have to check Massachusetts for every single town or city.  (In that case, I would have to put parent keywords such as Events in brackets too).

I hope this is somewhat clear.  Just trying to grapple with this before I start keywording.  Trying to minimize regrets down the road.