I think the four objections here can really be summarized as two: 1) there are energy/fuel losses involved in operating a fusion reactor which aren't present i

I think the four objections here can really be summarized as two: 1) there are energy/fuel losses involved in operating a fusion reactor which aren't present in other types of power source. This doesn't seem fatal to me; either we get the losses down low enough that this system is cost-competitive, or we don't. There's no way to know in advance where this tech will end up, and it doesn't seem like a reason to stop investing in R&D now. 2) Fusion as currently designed produces lots of neutrons, so there is the same sort of waste and proliferation concern as a normal (or fast breeder) fission reactor. I think this is actually the interesting one; the international community will not permit this tech to spread beyond the current nuclear powers if there's a strong proliferation risk. I hadn't realized that the current design of fusion plants were basically breeder reactors, and that's very significant; look at how the theoretically-appealing fast breeder fission reactors have been hamstrung for a prequel to this fight. Of course, if fusion gets to an integer factor cheaper than the next-best source, then it will be hard to keep a lid on this tech, but development is currently relying on many billions of dollars of research funding from the very countries that could be turning away from it out of political/security concerns.