In my wordpress theme I use the plugin TDO mini forms plugin for users to submit posts. The tdo form is in the footer of every page/post/archives. In my tdo form people write their content in the text box, then there is a drop down menu box where they choose the category where it will be displayed. I have alot of categories and it can be frustrating for people to search for a certain category. I want someone who can customize this tdo form so the category the person is currently viewing is the default category. For example if someone is viewing Category A and they scroll down to the footer where the tdo form is, the category drop down box will be automatically set to category A. The same goes for category B, C and so on.
I also want a plugin that will check the submitted posts to make sure it is not copied or the same content that is already in the category.
Let me know if you need any further explanation or if you have any questions.