Firstly - this is my own personal take on colourlover etiquette, written because there have been so many questions on this subject. I hope that other colourlovers will contribute to this thread and so make it more representative.
This is a very supportive and kind community. Tempers do flare, as you will discover when reading some of the threads below.

Commenting on the work of others
This is a controversial topic. You can read some opinions on it in this forum post. Briefly - many feel that if criticism is given it should be constructive, and that care should be taken to avoid giving offense. Others feel that this approach is limiting and not entirely honest.

This is something you will have to work out for yourself. Keep in mind that if anyone is found to be harasing another colourlover or repeatedly acting in a way that causes offense, the site administrators can decide to close down the offending lover's account.

Language - darnit! *@£$
You will find a "language filter" in your account settings. It is on by default, but you can switch it off if you wish to see what people really wrote. To find it, go to your Profile → Account → Settings → Swear filter. And of course, there's a group for explicit profanity if you wish to broaden your horizons even more.

Posting palette badges -
Posting a badge is a pretty innocuous thing to do. But be careful. Some lovers find the unsolicited posting of badges (particularly on their profile pages) to be a form of spam. You can read more about it here

voting - how low can you go?
Another controversial area! Here is a conversation you can read about voting.

One of the issues is that some find it offensive if a colourlover repeatedly gives one heart votes - especially if these are always "aimed" at a particular colourlover. This can be seen as an attempt to harass or insult and is referred to as "featherplucking". There is even a group dedicated to "voting up" featherplucked palettes.

Voting - can I vote for myself?
You certainly can. But should you? Here is a thread in which people discuss this issue.

Can I use the palettes / patterns / colours in my own work, and how do I acknowledge the creator?
Have a look at the Terms of use thread

Language - darnit! *@£$
You will find a "language filter" in your account settings if you wish to avoid reading "strong" language.

It's the other way around, I think. :) You can deactivate this filter if you don't mind "strong" language. Go to your Profile → Account → Settings → Swear filter

Should we link to this group too: http://www.colourlovers.com/group/explicit_profanity? (since we link to other groups)

There's also a filter for NSFW descriptions. I think it's also on by default.

P.S. I think you did a very good job, as usual. It seems a pretty objective and fair presentation to me.

thanks! I agree with your comments and am integrating them now.