Dear Michael,
thanks for your comment! I'm glad you found my intuitive approach to deriving the Heisenberg uncertainty relation approachable. It can be made more rigorous---for a start in that direction, I refer to the Found. Phys.-paper---but I think this is a virtue of this particular approach: it makes an otherwise 'mysterious' phenomenon somewhat more easily palatable, by connecting it with statements that have a readily appreciable intuitive import.
Thinking about the energy needed to extract the information is an interesting direction. In some sense, there ought to be a relation there---thinking about this in terms of energy and time, rather than momentum and position. But I don't have a clear intuition there yet.
You're right to note that this sort of picture sort of straddles the epistemic/ontic divide. In a way, I'm not so sure it's good to think of these as rigidly distinct---certainly, in some sense at least, what we know about something is not something removed, off in some Cartesian realm of 'thinking stuff', from the physical world: the stuff in our brains is ultimately physical, itself. Hence, what we can know, and how we know it, is in the end also a question of what there is, i. e. what sort of stuff supports our knowledge. There's too much of the old 'detached observer' still lingering in this picture.
Regardless, if you're so inclined, I think it's perfectly well possible to interpret my proposal in epistemic as well as ontic ways. This is, to my way of thinking, an issue that only further argument will be able to settle. So, perhaps it's a topic for another contest!
Cheers, and thanks again for your kind words
Jochen