Plot hole: When Bond first sees that Willard White is actually Blofeld in the hotel penthouse, Blofeld shows him how he has been impersonating Willard White's voice with a machine. But that only works through the phoneline - out loud it would be different.
Plot hole: Glass or paste stones would have melted during Franks' cremation. But we're supposed to believe they ended up in the urn. (00:33:38)
Plot hole: Other than giving Bond and Whyte the idea that Blofeld must be hiding out on the oil rig platform, there's no reason as far as Blofeld is concerned to have the oil rig on the map in the penthouse. Nobody other than Blofeld or Whyte knew about the map until Bond enter the penthouse, so it made no sense for Blofeld to have Baja, CA on the map.
Plot hole: When Bond arrives at the oil rig he is in a silver sphere with no windows, but he somehow knows which direction to go in. Not only that, the parachutes completely disappear.