To your first 4 paragraphs, you jump around alot to many different points. But I think I can best concisely illustrate that you and I are not working with the same basic semantics. For instance, I have definitely grown plants with simulated water in a Zelda game.

I think when you here computation, you should learn more about quantum mechanics and how systems are describe in terms of discrete pieces of information. As it is, we can implant electrodes in human brains and send artificial signals to them already and people begin to "see" things that are not there.

How does saying thinking is just a form of computation taking it away from brains? Why does thinking have to be something different from just running probability calculations given the current input and the likely next step including for a given output we can take upon given "input"? It seems that for you that the possibility is entirely out of the realm of possibility. It's not that thinking can't be explained by computation, it's that is must NOT be explained by computation.