As far as logging in as root goes - no no no. You should not log in as root on a regular basis - if someone gains access to your pc they will have full rights. If you make a mistake while logged in, you could wreck your machine/setup.
Far safer to use su for those times you need to be root.
Also, for security, it is safer to need a password. Once again, if someone can get access to your box you run the risk that they will be able to nasty things to your setup.
Yes, passwords are inconvenient, but it will save you from unnecessary grief.
Here endeth the lesson