I thnk that I would prefer a full implementation of smaller selection of classes/races, where the game world recognizes and responds appropriately, rather than a larger selection that the game world mostly ignores.

If Larian want to, and can do a good job implementing more player races/classes than the PHB, that would be great; whether in the released game or as later updates or as part of any DLC or expansion. More is better as long as implementation quality does not suffer.