[Inky]

You could possibly see the past or future by psionic means, though, and perhaps even astral-project to it.

The difficulty of shapeshifting has a small practical implication for those vampires you mentioned earlier, by the way. Either they don't have the gargoyle-face thing as in the TV series the thoughtforms are copying, or one or the other appearance is an illusion. This might mean that their real appearance (which might be the human one or the gargoyle one, but presumably the fangs have to be real) was visible in camera footage. (Not that they aren't fairly easy to spot with modern technology anyway, what with not having reflections and showing up cold on thermal cameras).