Your page is confusing -- it looks like a Marketo landing page with a form, but you are
also doing the MktoForms2.loadForm(), which is for embedding on non-Marketo pages.
Please try to simplify to only one or the other. If you use the built-in LP form support, you want to do the form setup code inside
MktoForms2.whenReady( function(form){ ... } )
if you use the embedded form, you setup inside
MktoForms2.loadForm( <instance>, <munchkin id>, <form id>, function(form){ ... } )
but not both!
Because the form setup is erratic/duplicated, the unhide code never actually executes (you can see an error in the console).
The unhide code as written only supports text fields, not SELECT fields. There's a clear reason for this: there's no such thing as SELECT type=hidden (in HTML as well as in Marketo). When you switch a field to type=hidden, it behaves as if it were a INPUT type=text, only not visible. So out-of-the-box I couldn't just unhide the text with all of the other choices in a dropdown, since Mkto doesn't send the other choices to the browser once you switch to hidden.
There is a of course a way to do this with a SELECT as well, not incredibly difficult but kind of beyond my
pro bono time right now... if you do feel like
contacting me to get it done, feel free!