The only thing I find more annoying that "fusion = totally 0 radiation" is the idea that it somehow will provide "free" energy. With any power plant, no matter the fuel, there will be cost of construction(with a limited lifespan) and maintenance. Same goes for distribution network.

It makes me wonder if we could improve fission reactors cost and safety, instead of performing biggest down scaling act in history of technology (700k kilometer Sun to mere meters)

I think OP meant "radioactive fallout" which would be the source of "long term radiation." Fission bombs scatter radioactive dust of uranium, plutonium, and fission byproducts that continue to emit harmful radiation for thousands of years.

A fusion bomb with no fission stage would have a massive radiation blast, but leave no radioactive fallout. 10 minutes after the bomb, radiation levels would be more or less back to background levels. Is my understanding.