I finally read this book to better understand the question. The political view that this book takes seems to be straight-forward, honest and difficult to deny. The basic idea that Nelson Kraybill presents is that John wrote the revelation during a period where there was relative peace between Christianity and the Roman Empire. However at this time in history Emperor worship had made it difficult to grow an economy (‘buy’ or ‘sell’) without committing fornication with Rome (‘going along with some kind of sacrificial meal in honor of the Emperor, or whatnot, in local professional guilds’). On the other hand the synagogue of Satan, refers to the growing hostility between the two camps (Jewish and Christian) both claiming to be the real Israel. In this political hotbed of undercurrent and the looming apocalyptic persecution of Christians, destruction of Jerusalem and then eventual destruction of Rome itself, is what the book traces.
The book does not try to explain each symbol in Revelation it just takes a broad stroke on the major elements, fitting them into this historical context and explains how the reader at the time would have ‘naturally’ perceived the icons and how that would lead to worship and allegiance to Christ, resisting the seeming infinite power of Rome.
First I would say, by the end of the book, I thought it was far better than any other I have read. I have not read a lot of history, but those portions which I have read, as well as the history in the Bible itself, made me sense a strong confidence in what the author was arguing. In addition he presents many pictures of coins with interesting images and icons and artifacts that seem to speak the truth themselves he is sketching.
With respect to the question, "Are there any intra-textual supports for this interpretation?", I would say a big YES. If we think of Revelation as a pure mystery that had no immediate meaning to its readers, we break away from the tradition of apocalyptic history in the Bible. As a whole many of what Christians consider as Messianic prophecies in the Old Testament, on one hand predicted a local political event and then only by unrealistic exaggeration indicated a higher fulfillment to come.
I think we can take this book as a very good starting point for the first wave of fulfillment of the themes in Revelation and in many ways as history repeats itself, especially prophetic history, we can use that basis to have a better current application and future expectation.