I thought I had this figured out.
I just got off a salesforce call. I understood if set up according to Skuid sharing directions http://community.skuid.com/discussion/8015488/troubleshooting-guest-user-access-after-winter-21#latest. That I would be able to not only read and write records, I would also be able to update and delete records.
I can write a record as a guest user but not able to update it?
Is that not the case?