Even as a sort of newcomer (played at launch for a few months) coming into this community it was immediately clear that it had a very rotten apple in it. So many lobbies that I have lost count now, IN1 arrives, insults someone, lately me, sometimes someone else and leaves. And you have already covered his posting behavior in the original post. the thing is I find in these lobbies is that there is always universal agreement to what a complete tool this guy is, but most people try to ignore him.
However, he is not going to change, he cannot now, its not like he is some 13yr kid being a jerk, he is an adult with an entrenched personality. The sad thing is he reminds me very strongly of a guy at work. Now I am actually a mate of this guy, most people despise him, he has his big personality flaws, his over-whelming arrogance, the conceit, the need to try and belittle others. But I can see why this guy is the way he is. In short because he is an intelligent but unattractive and lonely individual who feels the need to put up bullshit barriers so avoid getting hurt by the rejection he has grown so custom to.
I think it is exactly the same with IN1. He craves attention online in this small game community because he is scared of engaging with his own real world. He attempts to belittle and insult people to gain a sense of control over people, its a safety thing. And most likely because others throughout his life have have used power over him in a way he found deeply uncomfortable. We know he is very overweight, again a symptom of seeking solace in pleasure to escape other pains. He simply is the way he is as a way to compensate for his life which I would bet was comfortable in some respects but so lonely.
The real shame is he does try and be decent and takes so much time writing up guides and the like as he seeks the respect and acceptance of the community. But then reverts to his hang ups the next moment with completely unnecessarily hostility and attacks on players. Like the kid that was always left out or bullied by the supposed coolkids he admired, and now wants to be the coolkid and thinks that involves finding weaker types to pick on. Thus his whole pro-worship coupled with his constant attacks and insults on others.
Because I have spoken out against him in the past he often gets very aggressive and unpleasant to me when he can, but it does not bother me. I am a well adjust very happy family man at peace with myself, there is literally nothing he could ever say to me that impacts on how I feel about my good job, nice home, smart kids, and beautiful wife, and I actually find it quite sad that this guy has lived the life he has that has made him need to act the way he does to feel safe.
IN1 is not going to get better, I would wager he will get worse for years yet. One day he might actually let someone come into his life and he will finally start feel loved and wanted, and a lot of this bullsh@t will wash away, but until then we just have to try and tolerate his behavior. Try not to respond to it. Just try and be understanding that what he says is to try and make him feel better about himself, sadly, by trying so hard to make others feel worse about themselves.