-fontfile is just what font file the game will try to load if its not already loaded by windows (So if your using a custom font which isn't in the windows font directory you need to place the font in the games directory and use this parameter as well as the -fontname one). Its simply for people who didn't have the font (IIRC some people reported issues with the font being missing from there system or something).
-fontname is literally the font it will use.
If your hex editing a string and want to make it be smaller just make the characters you don't want to exist be a zero (As in the character with the ID of 0 not the number 0). No clue if it will work, but strings are normally ended with a 0 character ("Null Terminated Strings"
P.S The game technically isn't designed to use other fonts as it was originally hard coded for verdana, but i exposed them via the command line parameters in one of the patches.