This is a really, really nice summary of helpful stuff people should know. I have a few specific thoughts which may or may not be of use:
- There's probably a middle ground between a strong warning against "rent-a-coder" type questions and having nothing at all in there. Something like...
As with any online community, personalities vary. You'll usually get more, more effective help if it's clear that you've made a good faith attempt to do things yourself, and are stuck on a specific aspect of your problem, than if your question is very general or appears to require a lot more work on others' part than on yours.
- It might be worth explicitly mentioning thanking people if you get help in the CB. That probably is covered by "be polite", though.
- You could clarify the "first error is usually the most important" by adding a sentence explaining that often, subsequent errors are the result of the first one.
- Explaining how to put code in the scratchpad wouldn't hurt either--sometimes the question is simple, but it requires more code than fits comfortably in the CB.