Two questions about MVC, and Identity

Question

I am very new to identity and MVC, I am trying to create an MVC app as one of my first projects.

I have been able to follow a few tutorials and have successfully add

Answer 1

1) I would make your own UserValidator inherit from microsoft's UserValidator and handle your extra field.

Updated:

2) You can make your own extension method to get the extra field you added.

public static string GetSomething(this IIdentity identity)
{
    if (identity.IsAuthenticated)
    {
        var userStore = new UserStore(new Context());
        var manager = new UserManager(userStore);
        var currentUser = manager.FindById(identity.GetUserId());
        return something = currentUser.something;                
    }
    return null;
}