SpitfireIX
Philosopher
I don't have much input on your last question, but something tangentially related: computing could be pre-empted by assembly-line style calculating, as was done during the Manhattan Project: apparently calculations can be done much more quickly this way (with humans passing cards from one to the next, each doing a specific step in the calculation) that can be done with individuals doing the whole thing.
All I know about this I learned from Feynman's stories (particularly "Los Alamos From Below), in which he talks about how a team of girls could do calculations as quickly as the IBM machines that they had on order. They used the girls to help get the bugs out of their system before the machines arrived, but were surprised to find that the girls were as fast as the machines.
That seems to me that it could be a quite useful, low tech solution that wasn't implemented, for instance in artillery...
Thanks for the suggestion; I'll have to research that. (Not to mention it sounds interesting in and of itself, especially if Feynman is describing it.