It’s quite possible that I just haven’t been exposed to enough of the ‘native’ side of the Japanese lexicon. Everything I said is certainly useless when it comes to guessing kun’yomi of kanji, particularly when they’re used to refer to things that only exist in Japan and nowhere else. No amount of past experience is going to allow someone to guess that 七夕 is read たなばた, and with good reason: 七夕 is a character combination used in Chinese to refer to the same festival, but in China, and it’s almost certain that Japanese people celebrate the festival quite differently from Chinese people. Like I said, ultimately, experience is the most (and possibly only) reliable way to determine what readings are used.
With all due respect, I don’t stop at ‘fluency’ in the usual sense either. There’s a reason my criteria for declaring myself ‘fluent’ include ‘essays with proverbs and idioms’ and ‘reading… literature’: I have to be at least as good as a well-educated native speaker of my age, if not better. That’s my personal goal. As far as languages in general go, I’m quite an etymology nerd myself, though I don’t dig quite as deep in Japanese because it seems less common for dictionaries to break words down into root words and other units of meaning, which is common for European languages. However, that makes some sense since most Japanese words are much shorter than, say, complex terminology taken from Latin in English.
I simply felt that my position was being grossly misrepresented, and I was particularly riled up by the use of the words ‘dangerous’ and ‘this whole mess’. I mean, it’s true that the plethora of readings one kanji can have in Japanese is really quite shocking, even for a Chinese speaker, and I presume that’s what you were referring to as a ‘mess’, but in the heat of the moment, I felt as though I had been accused of contributing to the confusion, which was hardly my intention. Also, while it’s true that the vast majority of my exposure to Japanese has come from anime, the other things I read in Japanese include NHK news articles, dictionary definitions, and articles on Japanese usage, with studies from Japanese universities among them. Even if I might be overestimating the usefulness of my general rule (which I wouldn’t really call ‘golden’ in all honesty, since it’s riddled with exceptions), I still find that it’s been very applicable so far. Specifically, the more technical the language used, the more my general rule applies.
Finally, as far as ‘book-length replies’ go… I’m sorry about that. I probably could have been a little more succinct. At the same time though, even when I’m not upset about something, ‘book-length’ posts are standard fare for me on these forums: the more relevant evidence and explanation I can think of for a given topic, the longer my posts get. My replies on the ‘Short Grammar Questions’ thread are probably the longest in the entire thread. My past as a debater also means that I constantly anticipate possible questions and rebuttals, so I never stop shoring up my arguments and looking for holes I need to plug. It’s a habit. I mean, just look at this reply. I didn’t intend to write this much. Oh well. So yes, don’t take my reply length personally either. I acknowledge that your main point was valid, and that you raised good examples.