1-I added captcha in Registration and Login page but there is no option to generate new captcha (refresh option).
Image captcha module by default doesn’t support same. Either use recaptcha module that comes out of the box in portal or Download & Use https://www.drupal.org/project/image_captcha_refresh module on top of image captcha module
2-There is no option for hard block(permanent block) the user after failed login attempts in flood control module.
Blocking the user will have more problems. Currently, it blocks ip address. If user is blocked, if someone knows username they can make failed login attempts & block legitimate user.
3-There is no option to add more textfield in Contact form.
Out of the box Contact form doesn’t support same. Use webform module & create a new contact form that allows to customise fields in the form.
Webform module is available out of the box in portal. Just enable same & use it.