The schema is as it describes, simple. The only thing is... I kind of have one underlying problem with the schema. The UserProfile & Membership table both share the same primary key. I see a greater benefit in doing this:
UserProfileTable: UserProfileID, UserID, Email
Membership Table: MembershipID, UserID, etc...
Notice how each of the tables have their own unique primary key and they share a unique index UserID in this case. Wouldn't this be the better way to go about it? It just seems more flexible and better practice.