The only interpretative principle which I didn't see is an important one: Take into account the genre of the book.
For example, it is highly reasonable to assume that in writing a letter, or a summary of current events (i.e. a Gospel) or a history, one intends the simple declarative meaning of one's sentences. However, the same cannot be said of one relating his dreams in allegorical language. The fact that a writer continuously represents his actors as seven-headed beasts, etc is a clue to most any open-minded reader that he does NOT intend the simple declarative meaning of his sentence, but something hugely allegorical.
So, an important principle (which would save the author from his 'literal millenium' error) would be: Accept the literal, simple declarative meaning of a writing unless there are clues from the author (in the context or genre of the the writing) that he did not intend to convey such a literal recitation.
That is why I, like some others here, do not generally enter into the 'millenium' discussions: the 'dispensationalist' theories are based on the two most clearly allegorical books of the Bible (i.e. Daniel and the second half of Revelation). As such the hugely allegorical presentations are almost useless to us. The secret decoder ring for the allegoties has long since been lost (although I think that old John was probably providing a dream-like (politically safe) explanation of what was happening right then).
But the important point is that there is no question that the authors intended that a decoder ring was required. Once we take note of that fact, then treating them as simple declarative sentences capable of literal application is an abuse of the author's work.
The Lord will come again. When, I don't know. What He will do after He comes, I don't know. Call me stupid, but extracting anymore than that from dream-sequence allegories is merest speculation -- no matter what your preferred outcome.
Even better is to arrive at the "end" intended by the author. In this case, God being the ultimate author because all scripture is "God-breathed," we hope to arrive at the "end" intended by God. We assume, as opposed to some on these threads, that God actually desires an inquiring human to arrive at the correct end. "Ask and ye shall receive; Seek and ye shall find; Knock and the door will be opened unto you."
Given that God wants us to receive, then we could surmise that there is a God-ordained methodology that would lead us to the correct conclusion by a repeatable methodology such that reasonable others using the same method will arrive at the same conclusion with great regularity.
I would propose to you that those methodologies that enable interpretation to be all over the map - those that enable personal "interpretations" to rule on the meaning of passages -- MUST be wrong.
I have great concern over allowing a "genre" to rule over the words that actually appear within a writing. There is place that must be given for genre, but it should not be place that results in scattered or whimsical or various interpretations. Reasonable people reading the writing using a standard methodology must be able to arrive at similar conclusions.
This is my way of saying that genre does not rule over "scripture compared with scripture." If the context or if other scripture interprets a word or phrase symbolically, then I have no problem with it being symbolic. Most often the scripture will tell us what a symbol means.
If it doesn't mention that something is a symbol, then we should ALLOW, at least, that it is an open question. We should look at our interpretation with a literal application of the word/phrase and we should look at our interpretation with various reasonable "meanings" that might apply were the word/phrase a symbol.
I default to the words having greater import than the genre.