I think everyone who is whitelisted should be a guest, and cant do anything except walk around, or have a small handful of the things builders have. And If they really like the server and want to play, they can then apply for Builder, which would obviously be free. Just a little suggestion, as I think it would stop more griefers, etc...
I really don't like servers that prevent or extremely limit new players. :/ Doesn't feel fair at all. Plus, it would just add even more workload for all of the staff, when there is plenty to do as it is. Even if it did cause less grief (tbh, I doubt it would, since applying for builder would be free and easy), you would have just as much work, or more, with all those builder applications.
I don't rly like server's like this, because you can't do anything, and if you log on for the first time in the middle of the night, chances are you will get bored and leave, causing less people.. >_>