Automatic recognition of fields and change of kind

There's no built-in command to do that in Acrobat, which is why I've developed this (paid-for) tool that allows you to do it:

http://try67.blogspot.com/2010/10/acrobat-convert-form-fields-type.html

You can also get it from my new web-site, where's there's currently a "soft launch" sale (The discount code is available on the front-page): https://www.try67.com/tool/acrobat-convert-form-fields-type