Also, some apps, even in Tiger, may use FontBook rather than their own font display method. Probably only Apple aps and certainly not Adobe(!). Of course, most Apple installed apps can be recovered from the Installer disk(s) or even from Apple's download site.
As to how to remove extra files that are probably mainly in Preferences, you'll probably find an app that claims to do that and even more. I simply don't trust them to actually remove
only files that aren't used by another app, especially Adobe stuff that can sometimes be used by many of their apps but may appear to be part of one particular Adobe app. But the real reason I don't bother with them is that even if you remove all of those files, you may not even see the increased space show up unless you use Disk Utility to see the exact number of bytes used/available on the drive. YMMV.
If you can burn DVDs, the simplest way to 'archive' any unwanted files and still have them available if you change your mind 63.72 days from now, is to let the Finder make an archive of them in one large, DVD sized folder and use the "Smart Burn Folder" menu item.
The whole point is to do this 'house cleaning' as efficiently as possible. One can spend hours searching for apps, installing them, comparing them and using them and end up saving not much more than you would have simply dumping the files to a disk. And then discovering that something was moved that shouldn't have been! Oops! More time to waste doing repairs...
Of course, you can postpone, but not avoid the problem forever, by buying a newer, bigger drive! Time or Money. Two different solutions. How much of which is available or more important to ou?