It should not be any kind of disaster. General idea is to provide basic package which you should be able to extend according to your own needs - intergate with oath, integrate with LDAP and etc. Using standard Django apps for this should be the way to go. Would there be some kind of issues? You can always expect some kind of issues but nothing so strange we couldn't easily fix :)
The problem is just that some services don't provide an email, so if you allow registration with those the user cannot reset his password and cannot login with anything else.