The CSS Form Builder Help can be accessed online as well at the following address:
Do not rely solely on the Dreamweavers design view, it will not be a 100% accurate representation of how the browser will render the page. This is really a limitation to the Design View in Dreamweaver.
For the captcha code to display you must be accessing the form from a web server. This can either be a local testing server or a remote server. Also the PHP server must be configured to enable the GD library which is used to generate the captcha image.
We have tutorials for setting up a local testing server and enabling the GD library on the following page:
To enable the contact form to send an email, you will need to use the Universal Email extension. Form Builder is used to Create the form, you need to use the other extensions in the library such as Universal Email or Data Assist to add functionality to the form.