Question: I don't want all my users to create mysites and/or use social features. How can I accomplish this?
Answer: The "Manage User Permissions" link (under "People" category) in the User Profile Service Application's Central Admin page provides ACLs to accomplish this.
Question: How can I delete a tag or note from the system?
Answer: If someone leaves you a note on your profile, you can directly delete it from the profile page itself. For a noteboard on a team site, a user with full control permissions can delete notes directly. A user profile admin can also delete tags and notes from the user profile service application's central admin page, by using the link "Manage Social Tags and Notes" at the bottom of the page.
Question: I'd like to create different profiles, for example for a full time employee vs interns. How can I accomplish this.
Answer: 2010 has a new concept of 'sub-types'. These sub-types can be used to selectively use existing or custom properties for different types of user profiles.