Well, what you are saying is that, at least in the case of the harlot, there are definite cues given to John that it is not to be taken "literally". But this type of cue does not exist in the case of the woman in Rev. 12. In fact, it is quite possible for a strict literalist to take the woman as being Mary and be entirely consistent.
In fact there are many images in Revelation that do not have clearly identifiable cues that would require one to take them either literally or symbolically. The only thing that forces some folks to favor one over the other is the arbitrary assertion that literal is to be preferred over symbolic. I don’t happen to subscribe to that theory. It don’t believe it can be supported from the Bible.
And so when I read language like Rev. 20 about the "thousand years" I look in the rest of the Bible to see how big round numbers are used, and how they would sound to a person 2000 years ago knowledgeable of the Hebrew scripture. I turn to places like Psalm 50:10 where I read, "For every beast of the forest is Mine, And the cattle on a thousand hills." When God used phrases like "a thousand hills" He was not expecting that the Hebrew reader would go off and count out exactly one thousand literal hills and assign those and only those to God’s domain. The phrase "a thousand hills" was used to symbolize the fact that God’s domain is endless and covers the entire earth. I see the phrase "a thousand years" in Rev. 20 in much the same way. It is intended to symbolic the entire/complete time between the binding of Satan and the final vindication of God’s people. It is the time when Christ reigns on His heavenly throne and exercises dominion over the earth to bring many to salvation in Him. It is the same time outlined in 1 Cor. 15:25, "For He must reign till He has put all enemies under His feet."
One thing is certain, there is more work involved in comparing Scripture with Scripture to come up with the correct interpretation than it is to stick one’s finger in the air, throw darts at the possibilities, or glean insight from the New York Times in order to interpret it.
Concerning Psalm 50:10, you have to remember that it IS a song. Songs can reveal great insights, but often use poetical and figurative language.
Psa 50:10 For every beast of the forest is mine, and the cattle upon a thousand hills.
Now in English, that's not very poetical. But in Hebrew, it talks about cattle upon "aleph" hills, or mountains. Now aleph can mean a thousand, but it can also mean:
From H502; a family; also (from the sense of yoking or taming) an ox or cow: - family, kine, oxen.
So it's a clever little word play, a poem, that conveys God's power and dominion.
But Revelation 20 is something different indeed:
Rev 1:1 The Revelation of Jesus Christ, which God gave unto him, to show unto his servants things which must shortly come to pass; and he sent and signified it by his angel unto his servant John:
Revelation is SPECIFICALLY written to show us, his servants, what must come to pass. It's meant to reveal things. It's not meant to generalize. In the case of Revelation 20, Christ was VERY specific LOTS OF TIMES in a short space:
Rev 20:2 And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years,
Rev 20:3 And cast him into the bottomless pit, and shut him up, and set a seal upon him, that he should deceive the nations no more, till the thousand years should be fulfilled: and after that he must be loosed a little season.
Why not just say an "Age" or "a space of time"? Continuing:
Rev 20:4 And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshiped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.
Rev 20:5 But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.
Rev 20:6 Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years.
Rev 20:7 And when the thousand years are expired, Satan shall be loosed out of his prison,
Christ uses the specific number "a thousand" 6 times in 6 consecutive verses. It's as if he wanted us to REALLY understand something here. I don't think it's wise to take a Revelation from the Lord that is very specific and meant to reveal information and decide based on a poem that it's a general statement of an unspecified time.