These are the most common theories about what isis wants

The theory that they want what they say they want is missing, but I don't know what population you've been looking at to say what is most common.

to gather weird and unusual theories about what the true agenda of isis was

Your first three paragraphs suggested to me that you were interested in discussing the reality of ISIS. All weird and unusual theories are rendered false off the bat by their frankness about their aims and their actions in pursuing them. This is hearing hoofbeats and inviting people to consider what sort of weird and unusual creatures could possibly be causing them.

were they much more rational and more intelligent than most people give credit to them.

The whole post looks like a determination to fail the ideological Turing test.