Need a consultation from a good SEO

Hi guys,

I have the following question and I have no idea how to solve it.
I have a service and an application that live on, let's say, example.com. Pretty a soon, I will allow the users of my service and my application to share content direct from the app. The content will appear like this: example.com/content_url. Therefore, I am afraid of some things I have no idea how to cope with and even how to google them.
1. What if my users start sharing content that is not unique, or even fully copied from a different site? How will it affect my example.com ranking?
2. If there is really good content and some copied content, is there a way to automatically scan it and add noindex - nofollow tags to the duplicated content?
3. How will good and unique content will affect my web-site? Will it improve my rankings and help my example.com appear on SERP based on the article's keywords?
4. Will all those example.com/content_url be added to my sitemap?
And in general, how can such feature affect my site?
Thank you for your time and consideration!

If you are making an encyclopedia (just saying), then don't worry about content issues.

From the data you provided it seems that user will share content on you site using app, so let them share anything they want. As, your website will be a hub for sharing content. If FB, twitter block duplicate content then how can people share data there?

However, you can reduce the number of content characters (like in twitter), if you are much curious about content duplicacy.

In case your website services are like article sites (such as EzineArticles) then content moderation is the way to go! Because if you no-index user's shared content, they 'll not use ur service.

Hope this helps Good luck with ur service and app OP!