Hi,
sorry for late reply, it was night for us.
1. Easy Profile extends Joomla user management, so registration and edit profile pages are the same of Joomla. To add Captcha you can use the same way of Joomla:
a. Configure and enable some Captcha plugin from Extensions->Plugins (Joomla includes plugin "Captcha - ReCaptcha"
b. Set Captcha plugin from Users->Manage->Options
2. The best way to make this is to use a Text field type. Text field type allow you to configure a valid format:
a. in "Format" parameter ser "Custom"
b. in "Custom Format" parameter set "[0-5](.[0-9])?", see screenshot
3. Terms of services: you can use a required checkbox field type available only on registration form, to add description with article link you can add above or below the checkbox field a field of type HTML delimiter.
HTML delimiter:
http://docs.easy-profile.com/index.php/article/html-delimiter-field-type
Checkbox: see section "Fields only on registration (Terms of service)" at
http://docs.easy-profile.com/index.php/article/tips-and-tricks