Font Book vs. Suitcase -- System Font Issues
As far as what fonts are needed by OS X and what fonts you can ditch, I found the following from Extensis to be very helpful:
<b>Which fonts are absolutely necessary by Mac OS X?
Mac OS X installs several fonts in the /System/Library/Fonts/ directory right off the bat. Guess what? You can't move these fonts. Nope, there's nothing you can do with them. There are good things about this and there are some bad things as well. The good part is that by not allowing you to muck around in this font folder, the OS is guaranteeing itself that the fonts that it needs are always available. That's a good thing. It's a bad thing if you happen to have a font with the name Helvetica though.</b>
And also...
<b>Font Management and Mac OS X
Here a Font Directory, There a Font Directory, Everywhere a Font Directory
Depending on software installation and the number of users on a particular machine, there are four or more Font folders in Mac OS X. If you don't use a font manager, you may install fonts by copying or dragging font files to any of the standard Font folders in Mac OS X. Depending on which folder the font is in, the font will be available or accessible by different users. The following table outlines the different Fonts folders and the access that each provides.
Type of Use Font Folder Font Description
User ~/Library/Fonts/
The tilde character "~" is used to represent a user's Home. Fonts located in this folder are available to that user. Fonts located here are not available to other users who may log into the same machine.
Mac OS X does not require that any fonts be located in this folder.
Local /Library/Fonts/ Fonts located in this folder are available to all local users of the machine. Only an Admin user can modify the contents of this folder. This is the folder where Apple suggests applications should install shared fonts.
Mac OS X does not require that any fonts be located in this folder.
Network /Network/Library/Fonts/ Fonts located in this folder are shared among all users on a local area network. Typically, this folder is used on a network file server that is controlled by a network administrator.
Mac OS X does not require that any fonts be located in this folder.
System /System/Library/Fonts Fonts located in this folder are required by Mac OS X for system use and displays.
Mac OS X requires these fonts and as such it is not recommended that the contents of this folder should be removed or altered in any manner.
Classic /System Folder/Fonts/ Fonts in this folder are used by the Classic environment. These fonts are available to Mac OS X applications even if the Classic environment is not running. Fonts located outside of this folder are not available to Classic applications.
Mac OS X does not require these fonts but will make them available to OS X applications. Please note that this System Folder should not be confused with the Mac OS X System folder.
You probably have a font in your collection that is named "Helvetica". It's okay, we all do. But guess what? So does Mac OS X's System folder and according to that little tidbit above under no circumstances should you modify the contents of the /System/Library/Fonts/ directory. So what are you going to do with that version of Helvetica that is sitting in your UserName/Library/Fonts/ directory? Fear not, Mac OS X resolves duplicates based on the order of precedence defined for the standard Fonts folders. The order of precedence (from highest to lowest) is outlined below.
1. User Fonts folder (~/Library/Fonts/)
2. Local Fonts folder (/Library/Fonts/)
3. Network Fonts folder (/Network/Library/Fonts/)
4. System Fonts folder (/System/Library/Fonts/)
5. Classic Fonts folder (/System Folder/Fonts/)
But what if youve got more than one version of Helvetica in your personal font library? You cant have both of them sitting in your User Font folder. Thats where Suitcase comes in. Below youll find information on how Suitcase can solve these conflicts and much more.</b>
...Like you, I also ran into problems with fonts, spinning beach balls, etc. All of these occured after I had used Font Book.
I STRONGLY recommend you read the following page from Extensis:
http://www.extensis.com/products/2d.html
After a few attempts, I droppped Font Book like a bad habit. In my opinion it is not equipped to handle the demands of serious and reliable font management for graphic artists. It's not even close.
As for the spinning beach balls, etc... I had good luck using Disk Utility to Repair Disk Permissions. That usually fixed it... but the best thing I did was:
1) Re-install OS X 10.3 (Erase and Install)
2) Remove all fonts from /Library/Fonts
3) DO NOT TOUCH fonts in /System/Library/Fonts
4) DO NOT use Font Book
5) Place your basic "core" fonts in /Library/Fonts (inlcuding, say, PostScript Helvetica, PS Courier, PS Times, PS Symbol and PS Zapf Dingbats if you use them)
6) Get Suitcase X1. Install it and set up your fonts in it.
7) Repair Disk Permissions from time to time
8) If problems persist, go into /System/Library/Preferences, delete the Suitcase .plist file, and the Suitacse Preferences folder. Re-do all your font sets in Suitcase.
I hope SOMETHING above helps!!! Good luck!!!