A form on the profile to do what? or do you mean you want users profiles to be public? If you want users profiles to be public adjust the Profile View Access Level parameter in CB > Configuration > User Profile as needed. If you need a custom form on their profile you'll need to be more specific as to what you're wanting it to do.

There's no functionality for that. CB is not a custom form builder extension. You'd need to look into extensions like ChronoForms and RSForms. Aside from that you could use the email user form by setting "Email Handling" to "Display Link to Email Form" within CB > Configuration > General. You should then see a menu item on their profile on the CB Menu bar above the canvas image to email them. If you need it to have public access ensure you also set "Public Email Form" to "Yes".