1. The neck pickup does get in the way. I could however have the bars go into the neck, and weld them to a metal plate, which would surround the neck pickup and be covered by wood.
2. The neck would probably be held in place good enough by the string tension, and epoxy should do a good enough job.
3. Some metal, hardened steel or something. But in what way they would counter act the truss rod, I can't see. The bars would not go deeper than maybe to the 19th fret (24 fret neck), and the truss rod has nearly no effect at all out there.
4. Got access to a drill press.
5. Bars = $10 at most. Epoxy = $5 at most. Ready made through-neck = $194.85 (stew-mac)
I still think it's very possible, and less time- (and money-) consuming to convert. But I'm not so sure if I wan't to be without my KE3 for as long as it would take, and of course, there is a risk of doing something very wrong, so it would take even more time to fix.
If someone has a guitar laying around, and is willing to donate it for a tut, I'm willing to try, though.