This is a well-told story. It does bring up the question of why anyone would (or would not) have recanted of their accusations in regard to witchcraft. What psychological pressures were suspected witches under? Did those pressures include discouragement of recantation? Was the discouragement active or inadvertent?
How well is the witchcraft-craze itself documented? This may have been made of the same material as the various "urban legends" of modernity.
A fair amount of trial transcripts and other related material has survived -- some three volumes worth of court records alone. Cotton Mather wrote a letter at the outset of the judicial proceedings to Magistrate John Hathorne (Nathaniel Hawthorne's kinsman) warning him and his fellows to be exceedingly careful with "spectral" evidence -- Hathorne didn't take his advice (and Nathaniel was more than justified in judging his relative harshly).
But I tend to think, as Hansen argues, that there were indeed people who practiced witchcraft in Salem, and that it was effective in the sense that people connected ill events -- a cow getting sick, an Indian raid, a girl having a fit -- with the art of witches. I'm just not sure that that explanation holds up for the whole course of the witch hunt -- and again, it seems like Hathorne pushed it further.
As for my little reconstruction of Mary Warren's life -- the only really sketchy thing is whether she would have taken part in the "egg" experiment with Mercy Lewis, Ann Putnam and Mary Walcott. (Probably not, although possibly). I included it because it is more than likely that Mary Warren dabbled in that white magic. Similarly, every girl I knew in grade school had, at one time or another, played with a ouija board.