Build an online form builder with user management.

I need to build a prototype web application for a client for low cost. It will be used to test before we build something feature rich and branded (add design). The main purpose is to build an online form called an inspection report. How the web application works: User registers for website. Admin approves registration, user receives email that they are active and have temporary password, and can change their password. User creates their Inspection report selecting pre-made sets of form fields that we build. Users cannot fully customize the forms, it will be a predetermined set of fields. After The Inspection Report is created, user creates a password for that Inspection Report and sees an unlisted URL for the form. User shares unlisted URL with their clients and password, who then go to URL, enter password, and fill out form (inspection report). User receives and email once the form is completed, with the Inspection report attached as PDF and/or xlsx files. User can log in and see a dashboard with list of inspection reports submitted and view or download the inspection report. *Optional - User has to signup for monthly membership to have access through PayPal or Stripe. I'd like to use WordPress with a clean bootstrap theme, and use something like gravity forms. The requirements are: - Home page -- Login -- Register --- Admin must approve registration (in future it will go to Paypal and be active after successful payment). -Inspection Report Page -- only accessible by registered users. --- can create their own Inspection report ---- can create password for inspection report that they can share publicly with unlisted URL. --- can create multiple inspection reports and name them --- can only see their own inspection reports, not other users. --- can download their filled-out inspection reports as PDF or xslx --- receive an email when their inspection report is filled out. -- has default form fields (that we determine) -- Add form fields (pre created) The form will be based on the attached inspection report. Some of the fields will be optional. Can we build the form so that it has all fields, then change to make sets of fields optional? We need to build the forms first, then the user can select which field groups (that we determine) to use in the create of their form No graphic design required, will just use a bootstrap style theme. We can provide WordPress environment already installed on temp server. We just need form built, and user management worked out. Thank you.