There's a lot of interesting Greaseweazle-y floppy development being done at Adafruit right now. Some days they're posting multiple videos a day showing progress updates.
There was a nice talk from VCF West last year on signal analysis and filtering (focusing more on the analog realm than this article) to recover data from damaged floppies: https://www.youtube.com/watch?v=ZgH6ov33ieg
Maybe, depending on how they were stored. I haven't done an extensive amount of recovery but my Apple II disks from the late 80s, stored in a basement with little temperature fluctuation, ready-out fine in the mid 2010s.
I would encourage you to look at the Greaseweazel[0] in lieu of the Kryoflux. The Kryoflux has an onerous license that only permits personal use. The Greaseweazel has a comparable feature set and doesn't limit user freedom.
https://github.com/adafruit/Adafruit_Floppy
(here are some representative posts)
https://www.youtube.com/watch?v=KQvzZKNvRM0
https://blog.adafruit.com/2022/01/16/5-25-floppy-reading-wit...
John Morris's Applesauce floppy disk controller hardware and software project continues to add functionality.
https://applesaucefdc.com/what-is-applesauce/