As I have a simple fix; I'm not all that worried about it now
Well maybe you should be worried.
NULL is 0 so you are using pin 0 as RW. You might have trouble with grounding the RW pin.
I think you mean "You might have trouble with grounding pin 0". Let me try to clarify this.
Here is the problem with your 'simple fix'. By using seven parameters you are telling the library that you want it to drive a certain pin low. By using a 0 (NULL) for the second of those parameters you are telling the library that it is digital pin 0 that you want driven low. You aren't using digital pin 0 right now so you don't notice any problems, but if you were to try to use it you could run into unexpected errors.
Don