There wasn't much to start with, since the moorish conquest didn't displace the people but "incentivized"(ahem...) people to convert.
> How many conversos did the Inquisitors burn at the stake, generations after their ancestors converted, on the strength of rumormongering by jealous neighbors?
It's hard to know, but I've seen stimates around 3k-5k. Germanic wytchhunts probably had a much higher number of victims. The Inquisition was a pretty bureacratic institution, and it had proper trials with defence lawyers, questioning of witnesses, etc... Inquisitor [Alonso de Salazar](https://en.wikipedia.org/wiki/Alonso_de_Salazar_Fr%C3%ADas) for example, saved probably thousands of people by setting high standards in Inquisition trials.
Yes, it was VERY BAD and TERRIBLE, I'm not condoning it, but it wasn't the worse that humanity has seen. By far.