ishabana:
Your list is exactly right..this is the chain of process I am trying to reach.
I think you are simply after a few devices that can interchange data, both between themselves and other other devices, which are both local and out on the web somewhere. You have prempted any further comment on logic or practicality by labelling it "art". Depending perhaps on the nature of the data, Arduino stuff is very likely overkill, but fills the bill because it is capable, cheap, and easy to use. Unless you are buying it for reasons other than functionality, that Robotdyn thing is gross overkill and a waste of money.
There is nothing meaningless about IoT, it might be exactly what you want to painlessly extend your local comms to the outside world. That is it's job. The only thing that is really nebulous is the source of the data "from the internet" and the "something else", and both might not be the IoT. But that isn't an Arduino problem, or a problem for it, unless the data is video or something that might be too fast to be used.
Those ESP8266 stand-alone things are probably what you want, and not such an expensive mistake if they aren't.