I did not read all the long responses...sorry. Currently, that photo indicates an "open" system. In other words, the fuel vapors are free to escape (assuming valve is positioned to allow free escape of air/vapors for filing purposes). If the valve is working, then it allows vapors out and not in (along with dust).
This is not good for safety and the environment in my opinion. If you park in an enclosed garage, you can lose fuel vapors that can collect and ignite unexpectedly. This needs to be fixed.
The vent line is supposed to connect back to the filler neck ABOVE where the end of nozzle would be inserted.
