Facebook login redirection to the same page is not possible at the moment, due to the strict mode introduced by Facebook in the app settings.
We are not sure what is causing the problem with Vkontakte login. Would you drop an email at support[at]heateor[dot]com so that we can figure it out?
For apps with dynamic redirect URIs, use the state parameter to pass back the dynamic information to a limited number of redirect URIs. Then add each of the limited redirect URIs to the Valid OAuth redirect URIs list.