Ye' old general discussion board. Basically, for everything that isn't covered elsewhere. Come here to shoot the breeze, shoot your mouth off, or whatever suits your fancy. This forum is not for asking programming related questions.
You are allowed to add new variables to classes externally and they will be public. You should use get and set methods if you require more control. Have a look at __get() and __set(), where you can add your own code to run checks on variables you are trying to set.