Get data of user after login (but not with craft()->userSession->getUser()) Can I directly get the data of the user that I just logged in with craft()-&gt;userSession-&gt;login($username, $password) ? (not from a method that uses the SESSION like craft()-&gt;userSession-&gt;getUser() though)
If you have the any identifying information about the user (user ID, email, username, UID), you can use one of the UsersService's methods:

craft()-&gt;users-&gt;getUserById()

craft()-&gt;users-&gt;getUserByUsernameOrEmail()

craft()-&gt;users-&gt;getUserByUid()

craft()-&gt;users-&gt;getUserByEmail()

They will each return a UserModel object to interact with.