We have Gallery Plugin which Manages Images Only. If you have already uploaded many files and now need a way to show them as Thumbnails, we can do some customisations for you on your Production Instance. We have sent you and email related to this. Please communicate on that channel for further assistance.
The errors seems to be coming from the Condition where you are trying to send email to a Related Field. Can you confirm that the Related Field of the Record for which the Workflow is triggered has an Email Address?
It does parse Other modules and the main Module is the One which you setup in Workflow. We have not received the screenshot. Can you please check your php_error.log and share the message that you see there.
In the Create View, the record has not been assigned an ID yet, thus we encourage users to upload files after a record is saved. If this takes too much time or you need a better option, we do have a separate customisation of code that hacks the Record save process and allows users to upload files on the Create View.