A. It can have it's own members area look if you setup a membership for it. It will have it's own look, however, the members area would share the domain from the primary site that the piggyback is attached to.
A.Yes, there is a section called "Manage Email Templates" where you can create email templates to use multiple times. Once you've added an email template, you can use it by clicking the red email icon in the editor.
