Can I adjust the autoguider settings during an exposure?

Yes. Changes to the settings do not get used until you restart the autoguider, but you can just hit the "Stop" button and then the "Start" button again. Guiding will continue as if there was no interruption. This is possible because the autoguider controls are completely independent of the camera controls. Note that for situations where the main camera and autoguider share a shutter, you may have to turn off auto dark frame subtraction.