I like your style of writing. Though: too many ideas, difficult to rate and respond.
Karma always has a random component. Karma of one comment is not significant. Karma of 10 comments shows a trend. I have once received a negative karma for a comment showing an obvious error in reasoning of others; but it only happened once in maybe hundred comments, so I don't make a drama of it. But yeah, it might be painful if that happened to someone's first comment on LW.
Instrumental rationality is a known problem of intelligent people. My worst experience was Mensa: huge signalling, almost nothing ever done; and if something is done, it's usually always done by the same two or three people, who could just as well have it done on their own. Compared with that, people at LW are relatively high in instrumental rationality -- they have a working website, they write good articles, they do research, they organize meetups and seminars. But yes, we could do a lot better. Instead of going meta, people could focus and write about things they care about. Not doing this on a web discussion is probably a symptom of not doing it in the real life.
Yes, being convinced of one's own rationality can lead to overconfidence. I don't know a cure. Perhaps repeated exposure to disagreement of other rational people will eventually move one to update. Another reason for people focusing on what they are good at -- providing more evidence for their rationalist friends.
Re: last three paragraphs -- the choice to stay or leave is on you. Don't participate in the discussions you consider worthless, write something about the real things you work on. (And perhaps I should do the same.) But this is not a new idea -- we have regular threads "what are you working on" here.
Same dude here, despite the name. Hypothetical: Should a prof at, say, Harvard working on the genetics of longevity post and spend time here?
Discussing his own work would be identifying and probably not very productive. Let's further say he's pre-tenure. Top places have a very different tenure success rate than even very good places, so it's an iffy point in his career.
Does Less Wrong have anything to offer him? And doesn't he serve Less Wrong best by staying away and working? (or even "playing" elsewhere)
My central criticism of this place ...
I'm worried that LW doesn't have enough good contrarians and skeptics, people who disagree with us or like to find fault in every idea they see, but do so in a way that is often right and can change our minds when they are. I fear that when contrarians/skeptics join us but aren't "good enough", we tend to drive them away instead of improving them.
For example, I know a couple of people who occasionally had interesting ideas that were contrary to the local LW consensus, but were (or appeared to be) too confident in their ideas, both good and bad. Both people ended up being repeatedly downvoted and left our community a few months after they arrived. This must have happened more often than I have noticed (partly evidenced by the large number of comments/posts now marked as written by [deleted], sometimes with whole threads written entirely by deleted accounts). I feel that this is a waste that we should try to prevent (or at least think about how we might). So here are some ideas: