I answered in red text on some of your specific sentences.
I'm a rather new player in MMOs and I've been using Noxxic for WoW, mainly because it was the first thing shown to me, and for a new player like me, it was very clean and appealing.
With time you realize that written guides aren't supposed to be a "rule" of how to play the class but as an actual guide to help you move forward. It lets you get familiar with your class that's all.
As you said - Force Potency doesn't stack with Force Technique Force Breach (at least that's how I understood it), but that doesn't matter IMO. If Force Breach doesn't proc it, then Project will, or Force in Balance, or Mind maze etc.
Its not reliable - I could argue with that, but then again, no other guide is. That's why there are other resources available, but none of them are clearly better then any other guide. Some may be more detailed on explanation then other but that doesn't make them any better.