You can see all the topics you've posted to using the "My Posts" above (__doPostBack('butShowMemberPosts',%20'4');)

For the subscriptions, the control panel link above (below your name) takes you to a menu. In it are

Forum Subscriptions:http://www.sqlservercentral.com/Forums/ForumSubscriptions1.aspx

Topic Subscriptions: http://www.sqlservercentral.com/Forums/TopicSubscriptions1.aspx