(1) The default UserList lets the "Sysop" read and kill any messages in any message category, even private ones. You will, therefore, want to change the Sysop password to something only you know. Click on the Userlist button on the main control panel, find the entry for Sysop, and edit the password.
(2) There are pre-login, post-login, and new user notices, plus titles on each message section. These can all be changed by logging in locally and editing them as they appear.
(3) If you're using a 2400 baud modem, check the "2400 baud" checkbox on the second card of the home stack.