What I find absurd is that one could think that physical limits on technology are absurd. Physical limits are exactly the limits on technology, no more no less. The question is what those limits really are and in some cases we do not yet know them but for the most part we have a pretty good idea of what is and is not possible technology wise. It is simply up to us to try to maximize our potential within those limits.
I don't think so. We have no idea what those limits really are. What you're saying now would be like someone from the 1850s, before the invention of electricity, claims that there's no way that we can communicate instantaneously with people on the other side of the planet, actually scratch that, make that people from the next town over, because PHYSICS! I mean, it just isn't possible because we're limited by the physical distance, right?
I think it's silly to think that we can even predict what the new physical limits will look like in 100 years. At least I hope that is the case. Still pissed off that we don't have flying cars yet though.