By itself the density of such a system would just be an interesting superlative: the paper itself references people who have achieved similar densities in the lab, but it's not necessarily useful if the read and write are slow and the total addressable area is miniscule: both things I would expect from the described proof-of-concept (the main point of which would be to demonstrate that the storage works at all, and maybe to evaluate its robustness to some degree).

You should not expect that even the best of ideas at this stage are going to turn into products on any reasonable timescale, this is at a super early level of development and there are probable more things that can go wrong than you are imagining. But the paper shows there has been a good amount of effort at this stage to evaluate the robustness of the storage: the whole reason for this particular arrangement seems to be that it's pretty robust while still being writable. (though anything nanoscale is not something you're going to be able to handle directly)

The scanning-probe claim is real — C-AFM on fluorographane is achievable with existing commercial instruments. The paper is a computational prediction with a detailed experimental protocol. An experimental collaborator is preparing the validation now. The 'live conditions' question is addressed in Section 5 (radiation hardness, mechanical damage, defect physics).