If you are looking for a guide about exporting customer accounts (that were created with Facebook Login) - check this step by step tutorial.
If you migrated customers and if passwords of old accounts do not work - read it. You will find solution for this problem.
In this guide you can read how to create siteKey and secretKey that are required for reCaptcha feature.
In this guide you will get an step-by-step guide related to StopForumSpam service API key that is required for module that blocks customer register form spam.