A. The home page action is what a person should see when they visit your domain name without any file/user/folder specified (YOURDOMAIN.COM). For example, if your home page action is the admin's capture page, and your domain name is YOURDOMAIN.COM, then when they visit YOURDOMAIN.COM they will see the admin's capture page. If you select "Other Page" then you should specify the URL of the page a person should be redirected to in the "Home Page Action URL" box below it.
A. From advanced features, next to the page you want to redirect click the edit button, then there you will find something called "redirect url" just fill it with the url of the landing page you need it to be redirected and be sure to put this at the end of any redirect url you put : ?user=
~username~ A. You can create optin forms using HTML form creator.
You can add custom fields and copy/paste the code to your 3rd party website.