Actually, I know someone at AA who was an inactive employee but had constant access to company's non-rev website (jetnet). He could also list and do all other fancy things. But he could not check in for any flights. He once tried to check in at the airport and was told that the system would not allow him to check in, although the agent did not know why. Of course he knew so he promptly left before he would get in trouble. He even tried to buy ZEDs and even that did not work. So as you can see, having access to the system and being able to list does not mean you can actually travel, when it's checkin time, you will be denied as the system wouldn't follow through with it.