So, the best thing to do is always to leave it in LIBPATH and delete the regedit entries?
I think it would be better to simply change the "enabled" entry from 1 to 0, for all programs that are listed. As near as I can tell, there are possibly 3 places in the registry that are affected. It depends on which version(s) of font engine you have ever installed. ]
It is essential to NOT use the font engine with the later Mozilla derivatives, They do that themselves, and doing it twice is a sure to cause problems. NOTE that OpenOffice, apparently, uses the fontlib support, but OpenOffice should not be set to use the fontlib.
To make it simple, there is a GUI app that adjusts those entries for you. It says it is a beta, but it seems to work well:
ftp://ftp.netlabs.org/pub/vxapps/ft2gui/ft2gui20beta3.wpi