The things you list in your title aren’t forbidden by the laws of physics, they’re just engineering problems. If you’re going to speculate about the capabilities of a mind 100x smarter than you, it’d be worth considering what a dog thinks about chip manufacturing. Now, while you’re considering this perspective, consider how much smarter you are than your dog. It’s not 100x. It’s not even 10x.

A better discussion topic might be to point out that our DNA grew up in a linear world. Our primal intuitions about change are that things will probably not change that much. In an exponential world follow the evidence, not just your intuition. If you think an exponential will stop, make sure your reasoning, at its core, is not “it feels like it has to stop” or “it seems too good to be true”.