There already is a raid leader role assigned in LFR. Also, loot cannot be distributed other than random role or the RL would just queue with guildies and only give them loot. Only way that would work is if you could not queue in any type of group. Purely solo queue, and if you ended up in a raid with anyone else from your server, or any of your friends lists, then the RL role would automatically go to someone else who was in the raid alone.