YoVille will NEVER ask for your password, so please be wary of malicious emails and/or forum posts that request your password, including via web links.
If someone has posted after you, you can't remove it. If you notice you've double posted before anyone else has commented, you can delete the post with the x next to the edit tab. You can edit it at any time though. Don't worry, I've noticed for a while that posts are cloning. Sometimes the second post disappears. I'm not sure if it is removed manually by the moderators or if it just corrects itself. It's really no big deal
did not know you COULD accidentally post 2 times for a contest. If that is the case, I wonder if people who post 2 times accidentally will get double the votes?