But is there really one proper interpretation? Or two? If this were so, then why would the texts have erred on the side of allegories and/or parables?
As noted above, (absolute) language is flawed and inadequate (some more so than others) in describing any spiritual experience - i.e. anything pertaining to the inner world. Anyone who has had experiences and tried to share them with others knows this. Indeed, language itself has evolved phrases to illustrate this stark shortcoming: "I'm speechless", "There are no words....", "Words are not enough...", "I'm at a loss of words", "I can't find the words to...", "A picture is a thousand words...". And even with language, we gesticulate now and then when we're at a loss of words to render an exact experience with no details spared. (Which is why telepathy is a thing, if you believe in such things).
You are missing one thing. Understanding does not come through intellectual discourse... Or words read in a book/on paper. Understanding comes through direct individual experience. Hence the teachings are really a "guide" (which explains the parables/allegories), and people that 'teach' us are not really "teachers" in the Western sense of the word, but rather "guides".
Thus, a parable being a "picture with words", and a picture being a thousand words, what better way to 'teach*' than to paint a (verbal) picture...? - Indeed, we do it today when someone does not "get" us: we use "analogies", "scenarios" or descriptions prefaced with "let me paint you a picture...".
All of Bhudda's teachings merely point us along a direction, and Bhudda's teachings were different for different people. - Because people ARE different.
Interpretations are as diverse as opinions and subjective experiences, and yet, any of them that leads (read: guides) anyone to enlightenment is a "proper interpretation".
But be aware that reading alone, or "interpretation" alone will get one nowhere. Beyond reading, there is practice. And practice is more important than reading. Or any interpretation. Bhuddism after all is a "way of life".
If we "can't make sense" of Bhudda's teachings, it might be because we spend more time reading, than we do practicing....
"Even if we can't make sense of all of Buddhist teaching, at least we can read the texts properly (in proper contexts)."
- Reading is not a prerequisite to Bhuddism, nor to enlightenment???
As for a desire for objective study of the teachings, Enlightenment is not an objective experience, It is a very subjective one, and there is no one sole path that leads to it exclusively.. Nor can we lead anyone else to enlightenment, short of pointing them the way... So, which is more important? The study of it or the experience of it?