Problem with Simple Custom Forms
Design and Skin Customization
There are 2 issues here:
form_content - this is a LOCKED field, and is currently required. You CAN however change the groups to have it only show to say "admins", and that should hide it.
the name of your "customer name" field is "form_name" - this needs to be changed to something like "form_customer_name". The problem is that "form_name" is already being used internally, and that internal usage overrides yours.
So I will get a ticket open to make sure that fields cannot be created that could clash with the custom forms module (since the form designer is handled by the CORE and the custom forms just uses the core functionality).