[chrsw]

I'm leaning "no" and "yes, for what we know so far" to your questions.

I think tools are fine depending on how you define a tool and its relationship to human intelligence. If we build an artificial pancreas that learns about the body its sitting in and is able to function just as well as a natural pancreas would we say humans solved this problem? In some sense because humans built the machine. But not in another sense because humans are not the machine. Just like we say "AlphaZero beat the world's best human chess player". We don't say usually say "the humans who designed AlphaZero beat the world's best chess player". Did the humans who designed AlphaZero master chess? Not necessarily.

My argument is that there are examples of cognition that we know the human brain currently doesn't operate in. Are these learnable by the human brain? We don't know yet so we can't say the human brain is completely general.

As I type this and as you read this our bodies are constantly rebuilding themselves. Maybe if you connect the appropriate actuators we can do the same thing with our conscious minds? I highly doubt it due to the nature of the problem and how inefficient the brain would be in solving this sort of problem. It likely wouldn't work, but it's too far for me to say "rovably beyond the structural capability of our brains". I'll just say "I'm very pleased I don't have to do that right now". Developing a living organism, either starting from a single cell or from a fully grown adult, in real time in the real world is a very difficult problem to solve and the human brain would be terribly inefficient at it.

These are just my opinions.