Sortagrey, you should realize by now that the rear wheel is a compromise due to the dishing needed by the gearing. Having said that literally many millions of less than perfect machine built wheels roll around every year hauling folks that are both small and large. They do this with little attention from their blissfully unknowledgable owners until sometimes a spoke snaps. They'll often ride the bike with the broken spoke for a while before doing anything about it. So a spoke or two breaking isn't generally going to cause a full on wheel collapse instantly. Especially if you stick to higher spoke count wheels.

So while all you've written about is actually going on in a wheel it's not anything that you need to lose sleep over. Build your wheels using some care to tension, stress relieve and true them well and they'll be fine. For your first builds stick with 32 spoke designs using the tried and true 3x pattern on all sides. If you build them decently and reach the sort of tension ranges needed on the DS and NDS you'll find that you need little or no re-truing for many years. But since they are your first builds and we are all just human it would be wise to keep an eye on them by inspecting the tension and trueness reasonably frequently for the first few hundred kms.

Is the use of fairly extreme dishing such as we see on modern 9 and 10 speed rear wheels a good thing? No, it obviously has a lot of compromise involved to make room for that many gears. But while there is a compromise that affects the spokes it's equally true that many hundreds of thousands of wheels that are out there carrying the latest ultrawide 10 speed (and now 11?) cassetes are surviving just fine despite potholes and other road hazards. Hence my suggestion above that you're overthinking the issue.

Many things come together to result in a wheel collapsing like you saw in that picture. And often they all have to happen at the same time. The odds of that are slim but if it does happen it won't be due to any sort of failure from hitting potholes which loosens and jams the spoke heads in a decently built wheel.