Nope - you cannot do any work at all on Retirement according to the legal requirements.. In practice though how would anyone know if you are working remotely? I know a few on Retirement work as consultants in their old industries. They tend to fly out for these short assignements though.
I do not even think they exist. Immigration have been very hands off with the DTV. They took 6 months to issue guidance for extensions. I think it is common knowledge Immigration are not fans of the DTV.