I use the following free WP plugins in my adult wordpress sites.
Akismet : For moderating blog comments and trackback spam
Yoast WordPress SEO : This plugin is all you need to cover all the SEO needs of your post
Backup : Simple and easy backup
Better WordPress Google XML Sitemaps : Best...
Attention: "role based name" email prefixes such as support, webmaster, info, contact, forum, service, affiliate, admin, traffic, partners, marketing, etc., for our member accounts are not permitted. They are acceptable for a vendor listing, but not for the member email. This is due to bulk email processors scrubbing them for delivery due to extremely high bounce rates. Please apply for membership using a personalized email prefix. Something like email@example.com.
If we discover you signed up with a role based name we will give you only one message to change it. After 3 days your account will be removed if the email is not changed.