Thanks for the comment! I always enjoy hearing what people think of my stuff.

Since the ownership of the Library is determined by ruling adjacent clearings, it seems like an insurgent faction could get stuck with a limiting ability and be unable to shake it.  Do they just need to persuade the rest of the table to target someone else?

Insurgent factions definitely have a harder time ruling the clearing, and I tried to design the Historical Note abilities in such a way that were more punishing / limiting to militant factions in general. I specifically had the WA in mind as the sort of benchmark for how the abilities should be designed. "Poet Warriors?" was also an attempt to have insurgents care about having presence around the Library even if they couldn't rule any clearings around it. You are also correct that most Insurgents would likely need to negotiate with another faction in order to activate Revisionist History and get rid of their negative ability. 

Also, is there a rule to break ties in the Revisionist History step, or does it just get skipped if there's no single ruler?

If nobody has the majority, the step is skipped entirely as everyone fights for control of the narrative. Originally, I considered having the Scholars break ties, but I figured it would be more interesting if the condition was stricter.