(Before asking my question, I'd like to make clear that all of my previous knowledge comes from sources other than the suttas).
Is the buddhist doctrine of kamma a superstitious explanation for what is happening in the present?
How do the suttas explain diseases, malformations, intelectual handicaps and random misfortunes? Is there such a thing as random misfortunes for the Buddha (as exposed in the suttas)? Or can all of my present circumstances be explained and attributed to "my" past deeds? I ask this because I read in lots of places that some teachers explain diseases as consequences of our own deeds, and I not sure of how much of that come from the suttas themselves.
Another question, somehow related to the last one: As far as I know, the Theravada doctrine is not a non-dualistic one, and the suttas explicitly say that all conditioned phenomena are dukkha. But for other schools, is there such a thing as "bad" and "good" external circumstances? For those non-dualistic schools: do they accept that everything is dukkha? Or do they say that our minds are the ones interpreting things as good and bad, and as such, good and bad kamma is just and illusion?
Thanks in advance for your time!