From what I understand, Saavik's backstory is developed in the Movie novelizations, Pandora Principle, Unspoken Truth, DC Vol.1 comics, and Marvel Comics Untold Voyages.
1. Are there any other stories that develop her back story?
Those are the main ones, though a couple of others allude to aspects established in those various works.
2. Of these stories, which ones are consistent and which inconsistent? What details of her story are contradicted amongst them?
Everything else is consistent with the basics of what Vonda McIntyre established in the movie novelizations, but there are some differences of detail. "The Origin of Saavik" in DC's Vol. 1 had Spock rescue Saavik before TOS (flashbacks showed him in the pilot-era turtleneck uniform), while most everything else agrees that it happened a year or two after TMP. The other major discrepancy is that The Pandora Principle
says that Spock pretty much raised Saavik by himself whereas most others say that Sarek and Amanda raised her on Vulcan (with Untold Voyages
saying that Spock took her from Hellguard to the Vulcan embassy on Earth before eventually taking her to be raised by Sarek and Amanda). Unspoken Truth
acknowledges some elements from Pandora
(Spock taking a yearlong leave to tutor Saavik after her rescue) but also uses the "raised by Sarek and Amanda" version, and it portrays Saavik's time on Hellguard somewhat differently. This is the part where you find the most divergence among different versions, I think -- the details of what Hellguard was all about and what life there was like, as well as how old Saavik was when she was found.
3. Other than those stories and the Vulcan's series, Mere Anarchy and DC Comics vol.2, are there any other stories featuring Saavik?
She's in Dwellers in the Crucible
by Margaret Wander Bonanno, and in "Just Another Little Training Cruise" by A.C. Crispin in Enterprise Logs