issue 1. does the user have read/write access to the attribute?
issue 2: adding the requestlines to the request has nothing to do with the title of the request. Since associations are set using the object ID’s and not a attribute as foreign key or such.
Not sure what is not correct in your model, but each page of the wizard should start with a dataview with the Request object as context. If that is set, then you can add RequestLines to that Request object using the association between them.