Some things which are mentioned in the library books don't seem to be accessible in the current version. Like the darkness and light elements, along with the petrification status that you mentioned. There's also confusion and charmed which have not been implemented in any battle yet.
There's a build for patrons which lets you play as the enemies and Evie while she's an ally. If you max out your Allure trait as much as possible then Nel will try less to break free from struggles. Grapples mostly break in one struggle with her because letting her possess Celica increases her Luck trait which increases chances of breaking free of grapples.