I don't think I've managed to write myself into a corner quite yet, knock on wood. That probably will happen at some point, but luckily I've got a bunch of people helping me out to specifically avoid that.

As for a plot event I'd like to retcon? theres some stuff that happens in book 3 and 4 that I would like to handle a bit better, but thats mostly just changing when it happens in the story rather than how it happens. Which means that those sore spots get to be fixed on official release! One of the benefits of writing a web serial, I reckon.