Apparently, your driving habits will affect the functionality of the oil separator more than its age. If you do a lot of quick trips that allow condensation to form then you'll have problems - even if you recently replaced the oil separator.

Sorry, have no idea whats wrong with your X but it sounds like antifreeze is leaking in the engine bay somewhere. Does the X have a heater core? Could that be a cause of the smoke from the vents?

Weasel where are ya!