>> "I'm still mulling over the automatic trial feature, in general. Can I disable automatic trials and only use trial extensions? Do I just set trial days to 0 to make this happen?"
Yes, setting the trial to 0 will accomplish this.
>> "Can I cancel this current trial rather than actually waiting 30 days?"
No. But you can use the TA_ExtendTrial() function before the trial ends. We don't preset that option in the Wizard because it just adds unnecessary noise to the interface. But you can certainly add it within your app.