reduce passwords I must type
This is pretty simple.

In System Preferences 


go to the Users &amp; Groups Preference Pane
click on Login Options
click to unlock (bottom left) if needed and authenticate
verify Automatic Log in is on the user you wish to use
go to the Security &amp; Privacy preference Pane
enable your user for FileVault
reboot


You will select your user from the picker and then enter your password one time and then you should be logged in. If you have a bad user, you can add a new admin user, let it unlock FileVault - remove the problematic user but do not delete the home folder. Then rename the /Users/whatever (deleted) to be the short name you wish and re-create the user. Be sure the keychain is unlocked when that new user password is set up when you log in. Authenticate the new user to FileVault and remove the "new admin" user from above.