An addition to my previous comment:
I was surprised by your analysis of the book, which I enjoyed. I was not so surprised "by the prominence of Aram": because Aram under Hazael was the dominant power in Israel and Judah that were both vassals of Aram. Maybe the depiction of Hazael as a tool of Yaweh is a product of the exilic times? When the Jews tried to understand the destruction of Jerusalem, they came to see Babylon as tool of Yaweh, the only true god. Similarly, the authors in exilic times might have seen in Hazael in the first versions of the Book of Kings a tool that Yaweh uses to punish evildoers in Israel and Judah.
An addition to my previous comment:
I was surprised by your analysis of the book, which I enjoyed. I was not so surprised "by the prominence of Aram": because Aram under Hazael was the dominant power in Israel and Judah that were both vassals of Aram. Maybe the depiction of Hazael as a tool of Yaweh is a product of the exilic times? When the Jews tried to understand the destruction of Jerusalem, they came to see Babylon as tool of Yaweh, the only true god. Similarly, the authors in exilic times might have seen in Hazael in the first versions of the Book of Kings a tool that Yaweh uses to punish evildoers in Israel and Judah.