You never mentioned immutable. If objects were immutable then yes you are correct.
I'm not sure what you mean by "true business application" but there is a transient form of mutable state that an object possesses in between processing a request and returning a response that is seperate from the state that the database holds. It is up to you whether you want that transient state to be mutable or not.
An object itself cannot be evaluated. Methods can be evaluated but not the object itself. Is your example referring to a specific language?... because in general objects are not functions.