See How does code make it into WordPress.
See Reporting Bugs.
Check out Contributing to WordPress to find out what you can do and how to get involved.
Yes, it is. Please be sure to drop by the plugin author’s page and say “Thanks.” They deserve the appreciation and look forward to hearing about your suggestions and experiences with their work. This will no doubt help to encourage them to continue the development of their plugin(s).
If you have unchecked Allow link notifications from other Weblogs (pingbacks and trackbacks.) on the Options > Discussion panel, then you have only disabled trackbacks on future posts. To completely disable trackbacks, you will have to edit each past post and uncheck Allow Pings from the Write Post SubPanel. Alternatively, you could just simply delete the wp-trackback.php file, or run this MySQL query, from the command line on a shell account, or using PHPMyAdmin: UPDATE wp_posts SET ping_status=”closed”;
If you have unchecked Allow people to post comments on the article on the Options > Discussion panel, then you have only disabled comments on future posts. To completely disable comments, you will have to edit each past post and uncheck Allow Comments from the Write Post SubPanel. Alternatively, you could delete the wp-comments-post.php file, or run this MySQL query, from the command line on a shell account, or using phpMyAdmin: UPDATE wp_posts SET comment_status=”closed”;
Go to the Options > Discussion panel and make sure that An administrator must approve the comment (regardless of any matches below) is unchecked. With that option selected, all comments are sent to the moderation queue to await approval. Make sure that Hold a comment in the queue if it contains more than x links is not blank and contains a number higher than zero. If this value is blank or zero, all comments containing links will be moderated. If the option mentioned above is unchecked, the link moderation value is higher than zero, and you still have this problem, your Spam Words list probably has blank lines, punctuation marks, or single letters between the information in the list. There should be spaces between the listed items or each item must be on its own line. If you have done this, then upgrade the comment spam plugins you have installed. If this continues to be a problem, deactivate the comment spam plugins one by one to determine the culprit and contact the plugin author for help.
If you do not have comment spam plugins or the latest version of WordPress installed, this may happen. Upgrade or install one of the comment spam plugins and manually delete the comment spam from your Manage > Comments panel.
Comments that are marked as [spam] will be held in your database to educate “intelligent” anti-spam plugins, such as Akismet.