I agree with you that the Rohloff is the perfect gear train for a touring bike - if you can live with the gear change mechanism for drop handlebars (a must for me on a touring bike). I believe Rohloff are working on this issue and if they are not, they should.

As for the Rohloff dropouts, they are designed to do the job. The other solutions are compromises for cyclists who want to convert an existing frame. If you are having a custom design, go for the Rohloff dropouts. And when the replacement for a Rohloff comes along in 50 years, buy a new bike!

No thoughts on wheels but you should consider disc brakes while you are building this ultimate tourer. They are far superior to V brakes for a loaded tourer and not too expensive now. They will fit drop handlebars if you use cable operated brakes and not hydraulic. Make sure the pannier fittings are clear of the disc brakes.

Brian.