I think that not allowing people to download the beta versions might not be such a good idea. I think your best bet, is not allowing entering a S/N to unlock Executor, requiring a registration to get an unlocked version. This way, people can see the latest and greatest. Even if you don't allow DLing the demo, it will still make its way into the warez places. I would recomend allowing DLing the demo, and not entering a license number/serial number to open it up beyond the ten minutes.
