You need to compare scripture with scripture, do a Bible search on "cloud" as in the many times God appeared as a cloud, and study the prophetic language used throughout the bible about previous judgements. We are talking symbolic language here. The Bible interprets itself.
The known world at the time was the Roman world and the gospel was preached and spread to every part of it.
Not understanding the language is the error of the futurist, who expect the stars to literally fall etc. I thought by you understanding there was no gap in Daniels 70 weeks that you wasn't a futurist.
BTW - I am not a preterist who thinks all prophecy got fulfilled in 70AD, nor a futurist who thinks everything is future. I am a Historicist that believes the book of Revelation presents in symbols the entire course of history from the close of the first century onwards.
The Historcist perspective indeed does handle the scripture pertaining to eschatology much better, I do think it has a weakness in terms of audience relevance, John was writing to the people of his time and it had meaning for them.
I am leaning towards P or partial P /but I am only beginning to put it together by reading many of the great writers from the 1800's like James S. Russell.