I'm going to throw out an idea here that I don't have time to pursue, which may be of interest to those working with E-textiles and the like...
Instead of using conductive thread or wires, would electrically conductive gel (like used for TENS, EKG, EEG, etc) work? I'm not sure how well it would work for power applications, but maybe for low-voltage signals it would be ok? Get some really thin plastic tubing, and fill the tubing with the gel using a syringe. Insert stainless steel (or copper?) wire electrodes on each end, then seal the ends with some silicone rubber glue/sealant. Finally, use cold-shrink tubing on the ends to complete the setup.
I don't know what the resistance of electrically conductive gel is, nor what its voltage breakdown level is, etc (I tried to research this - but couldn't find anything via google quickly) - but it might be worth looking into (if it hasn't been already)...
