Length is only good insofar as it adds to meaning. Most length on LessWrong doesn't do that. For example, I can summarize your first point as:
Length is good insofar as it adds to understanding. Humans are not logically omniscient: if they aren't very close to understanding a concept already, a mere summary of the concept isn't enough to make them understand it. They need examples and supporting evidence.
Simply putting down a disclaimer allows you to marginalize issues that others might have with your post, it makes relevant criticism superficially appear less relevant.
Is this actually a problem on this site? I don't recall seeing disclaimers being much used that way here.
Upon reflection, this last point is basically the essence of my criticism. We've just changed the game to make it more superficially rational, but that is more resource intensive and it masks the underlying mindsets that are bad instead of actually changing them.
It's much easier to change institutions than it is to change people, and it's likewise much faster to get people to adopt social norms than it is to make them change their thinking. "Change mindsets not norms" might work in a closed group, but not on a public site that has new people joining all the time.
Today we're announcing a partnership with Castify to bring you Less Wrong content in audio form. Castify gets blog content read by professional readers and delivers it to their subscribers as a podcast so that you can listen to Less Wrong on the go. The founders of Castify are big fans of Less Wrong so they're rolling out their beta with some of our content.
To see how many people will use this, we're having the entire Mysterious Answers to Mysterious Questions core sequence read and recorded. We thought listening to it would be a great way for new readers to get caught up and for others to check out the quality of Castify's work. We will be adding more Less Wrong content based on community feedback, so let us know which content you'd like to see more of in the comments.