Before there was a "King" in Israel, God reigned from His throne and the people knew it. But they wanted a "King" just like the other nations wanted - so, God's throne became available to "man" to sit on it and reign over the nations people. That throne became "David's Throne" on earth even though it is God's Throne. God revealed that one of David's seeds will one day reign on that "throne"; and it happened when Jesus assended up to heaven to sit on it with the Father. You've seen the strong verses that indicate that conclusion - how do you understand them?
Those verses only indicate the conclusion if the conclusion is first assumed. You asked me how I understand certain verses. It is better to inquire about my understanding of the Davidic Covenant, which can ONLY be understood in the light of the Son of David ruling on the earth. The book of the Revelation affixes a time-period to the length of his earthly rule, a millennium. Attempts of amillennialists to disregard that time period fall flat.