Will you have any difficulties or risks with those features? Please write out them out.
Be very careful, because MOST startups fail because they do not think their functions/features through and they hit a technological barrier with very unintuitive work-arounds.
1. API Dependency: Some platforms depend on Facebook's Open Graph. The problem wish this is that your platform is dependent on Facebook. If Facebook bans you from their API, then you'll have to immediately find a workaround.
In fact, many startups had to shut down because Facebook's API policies kept changing, and they were not able to continue, because they depend 100% on Facebook.
2. Plugin Dependency: Your service is a plugin to other people's websites. The problem with this is that the website owner might not necessarily want to use your plugin. One good way to not be a victim of this is to be the content provider yourself.
3. High Difficulty: Many companies' core product is very extensive. While this is okay for products (like a search engine) that do require such scale, most of the time this is not the case. If you see yourself having to build a huge feature for your MVP, it's a good time to reconsider either simplifying your features, or think of a "light" version of your service to begin with.
There's a lot more, so think them through carefully.