@conspiratemus
Good insight, definitely an applicable comparison.

I can't help you with what kind of numbers you should shoot for (for tension) but hopefully someone with some understanding of the tension/compressive forces exerted on a bicycle frame under normal use will chime it. I would agree with Conspiratemus that you will need to avoid letting the wires unload enough to slacken and any failure is likely to happen at the connections as opposed to the wires. I would definitely select high grade hardware, with pins the size of the ones you pictured and eyelet ends on the cables with long swaged sections, which will probably have to be custom made.