It looks you were the right person to win the rims.
I did not understand most of what you said above 
But one day I'll build a wheel... Congrats!
LOL! The key to strong wheels is even spoke tension - all the spokes are sharing the load equally. On a MTB wheel, that's not possible because gears and brakes shove the flanges inboard. When they're not an even distance from the centerline, their bracing angles become different, and this means different tension needed to keep everything in balance. Imagine if you have a wheel where the right flange is 20mm from the centerline, and the left flange is 40mm from the centerline. This means the left side will have a bracing angle double that of the right, and as such will require half the tension of the right side to keep everything balanced. The problem there is that the maximum tension is dictated by the rim (something I'll have to find out from Peter on these) and so that maximum tension will happen on the right side. If the left side is at half the tension, then it's possible for those spokes to go slack in a big hit, and that's where spoke fatigue breakage comes from - loss of tension followed by a very abrupt rise in tension. It can also allow the nipples to turn which leads to things coming out of true.
So, with these rims and the offset spoke holes moving that point closer to the center of the flanges, what would be a 57% balance in the back becomes 72% - keeping the left side much closer in tension to the right side, which should make for a stronger and more durable wheel overall.
You should definitely learn to build a wheel - bike wheels are a beautiful thing - very few structures combine the light weight and massive strength of bike wheels, and when you understand how it all goes together, for me at least, it improves the riding experience. An initial build of wheels is not difficult - it can be tricky when you go with really lightweight components, though. Your first wheel build should always be as burly as you can stand. That'll also help cover n00b mistakes which might ruin a fancy/lightweight build.
