When user logged on, type "Login". Comes back with "password", type password comes back again with "Password" type password again. Comes back "login" incorrect. After successful login by typing login name instead of password, Keyboard key strokes are not echoed until <CR> is pressed. Pressing just <CR> does not echo Line Feed <LF>.
Unlike other un*xes, the Linux login is responsible for maintaining a PAM session, and so cannot support use from the command line. Try "su - user" instead.