Good write up and a good looking setup. I've just replaced some open pros with a velocity, the open pro fit inside the new sidewalls and the weight was only 20g difference. I have to say I noticed an improvement in ride comfort, I did stick with 23mm tires though so not a big difference, but out of the saddle sprinting and corner were much nicer, more responsive and more assured. I have to agree with your assessment that the wider, stiffer rims are worth the weight penalty. Unfortunately my frame won't handle a much wider tire though I think I'm going to outfit it with a 25 which is the widest.
I do find it funny that people worry that there's a thread or two showing on the spokes, I personally don't allow 2 full threads to show, but all these years and mileage later its the rim that failed and not the spokes being right to the bottom of the driver valley. Wheels are built to some amazing tolerances but at the same time still have a bit of leeway for what makes a perfect build. Glad spoke length worked for you.