Just imagine, theese type of players don't even know what happend at early 2009, when ff wasn't a thing, and the playerbase made mostly 3 different things: quests without town, building a town, or making fun in the game with "dueler towns", where were 50 people in one place with full of dueler gear, from level 15 to level 99, and they had only job: Kill everyone in the server. And I tell you a little secret: Nobody whinged for duels for some reason.1) make dueling an OPTIONAL choice, that you can opt out of, and not be dueled to death daily by players 50 levels higher than you, just because they want to be an A$$... so duelers can duel themselves if they feel like it, but those that hate the dueling aspect don't have to worry about it... and quit making ALL the events to where you have to duel and defeat someone in order to finish...
So if you buddy complaining about dueling, then this game really not the best choice. Duels are part of the game, no matter you like it or not, and EVERYONE should accept this. Can he make it optional? Of course he can, just do what @roland jacobs wrote 2 comments before. Simple as death.
Btw maybe your friend doing something wrong if he got denied from forum, or he just banned himself at the past.