Like some others here, I avoided this game as I knew it would suck the life out of me. I love that kind of stuff and find mildy amusing games addictive enough so I avoided it like the plague. Playing that game would have very likely cost me my marriage.
On that note you have some great examples of what to do in this situation. The game time needs to be limited (40hrs a week is not limiitng in my book, but each parent to their own) and is used as currency to get the right behaviour you are after - study and spending time with you and acting respectfully socially. Even if he improves these things as you say, it needs to be a treat, bad luck about the guild. Let him lose his life like that when he is 18 and can make his own decision not when he is 14. I guarantee if you provide alternatives, and remove the gaming for a bit, he will see that there is a big negative to just spending all that time playing the game - and having been addicted to various games previously myself, a small (total) break from it is usually all I require to see that.
On that note you have some great examples of what to do in this situation. The game time needs to be limited (40hrs a week is not limiitng in my book, but each parent to their own) and is used as currency to get the right behaviour you are after - study and spending time with you and acting respectfully socially. Even if he improves these things as you say, it needs to be a treat, bad luck about the guild. Let him lose his life like that when he is 18 and can make his own decision not when he is 14. I guarantee if you provide alternatives, and remove the gaming for a bit, he will see that there is a big negative to just spending all that time playing the game - and having been addicted to various games previously myself, a small (total) break from it is usually all I require to see that.