Think C defaults to Monaco 9 and tabs = 4. If you change either the font or tabs setting of a document to other than the default, Think C adds two resources, 'EFNT' (font) and 'ETAB' (tabs setting) to that document's resource fork. If you later change the settings back to the defaults, Think C will delete both these resources.
Why do some documents show up in that terrible Chicago 9 ?
Interestingly, if a document contains an 'EFNT' resource that specifies a font you do not have in your System (which can happen with documents you got from someone else), then Think C displays that document in Chicago 9, not Monaco 9. I would wager that the reason for this is that Think C tells the System to display it in that font, and then the System decides to use Chigaco 9 (the System default) since it doesn't have the requested font.
How Folder Fonterizer changes font and tabs settings
Folder Fonterizer first checks to see if the document even HAS a resource fork. If it does not, then it creates one. If it does, and it already contains 'EFNT' and 'ETAB' resources, it deletes them. Then it simply creates new 'EFNT' and 'ETAB' resources according to the settings you specified. Any other resources that may be present in the document's resource fork are left untouched (except the 'ckid' resource, which will be deleted if you specify to do so using the "Orphan files" checkbox; see balloon help for more details on that subject)
Does Folder Fonterizer change the modification date? No.
