As an aside many of these same issues are discussed when Joshua quotes from Timaeus at length in Episode 327 of the podcast (to be released later today or tomorrow). This appears in depth around the 15 minute mark but much of the episode is devoted to it.
The importance of these issues is why we are currently going through "Academic Questions." Plato makes very clear in Timaeus that the impossibility of stating anything about this world as more than "probable" is central to his viewpoint.