These are all really great answers, did not expect this many replies.
I just assume that since the door is unlocked that they are open to general public, including women, therefore there is no obligation for part 2. From the few times I have been to True Thai (I always go around 2pm), it seems quiet. I figure they'd prefer to massage a legit customer over no customer at all. Also, for $45/hr, it is a great deal. I can't really see a reason to go to a legit store if it is more expensive (I guess it would be a better massage). I don't have health rebate available (I'm 23 and not sure how it works).
Every time I have been to True Thai or Ruan Thai, they take my undies off for me and offer extras at the end. I will let them no when I am not after extras. Thanks guys!