1. Auto follow does not work if game is running at more than 60 fps. You need to have a 60 hz monitor and enable Vertical Sync. If your monitor is running at more than 60 hz, then you can't fix it.
2. Use HeidiSQL to make a second realm entry in the `realmlist` table of the `realmd` database. For the first realm put the public ip of the host machine in the `address` field, and for the second realm put 127.0.0.1. Your friend will use the realm entry with the real ip, while you use the one with the loopback ip. There will only be 1 realm in reality, but there will be two options on the list in game, allowing both external and internal connections.