The problem is the bot detection they have now, even private amazing scripts get caught easily. If you want to go for profit i would NMZ by hand on 6 client windows. You can max all 6 in 30-40 days if you invest the time.
Most profitable of all the online games? decent indicator might be all the games labeled 'Hot' on playerauctions, i think blade and soul might be profitable, and also possibly botting on Path of exile and selling the orbs your bot finds.