So, it seems that if you want a Web Form available for use (edit and create new) to Content Managers and below, it can't be uploaded and then registered with the Web Project; you have to Edit the Web Project and use the Create Web Form button on the 3rd page of the wizard to upload the forms anew. I see this as an issue because it means the same Web Form cannot be shared among multiple Web Projects in the same repository. I guess reuse is not supported by Alfresco in this way. What a pity.