If my understanding is correct regarding Evernote Enterprise having feature parity with Evernote Premium, then note versioning is supported so that you can revert to previous versions of a note in case of accidental edits. It still would be much better to prevent accidentals in the first place by having an explicit 'edit button' to change to edit mode and 'finish button' to change back to read-only mode for a note. A feature that seems to be easy to implement, but without any knowledge of what the technical backlog looks like, source code, or in-depth understanding of Evernote architecture, it is difficult to tell.
As for delete confirmation dialog, Evernote always asks for user confirmation on note deletion even for Free version (I think) -- there is a post in one of the forums asking an option to turn delete confirmation off for being too annoying.
