I don't know about that exact spot but I have seen similar details cast into yamaha crankcases - for lodging in a wedge and prying them apart (to break stubborn gasket cement). But yeah, seems odd just there?
The 'smoke' out of the crankcase breather is normal, its water vapor that 'steams' off the oil when the engine is at temp. Factory airboxes usually have the breather air recycled into the airbox so you never see it.