Right you are Klavan on the Culture! If I may add to your list of tips for pundits:
4. Do not pontificate on subjects that you are bone ignorant of.
5. Remember that taking a middle course on an issue is not inherently going to be the correct course.
6. Whatever else you do, try not to bore your readers or listeners.
7. Brevity may not be the soul of wit, but few people are going to read much beyond a thousand words of most blog posts.
8. Winning a debate and finding the truth are not necessarily the same thing.
9. In all things charity, and sometimes the most charitable thing you can do for a commenter is to delete their inane ravings.
10. Keep a sense of proportion. You are giving your opinion, not descending from Mount Sinai holding the tablets of the Ten Commandments.