Your original version had no license check and the information I have says that as of three days ago your license checking system doesn't work. I can't confirm that though since I haven't seen an updated version from you since your original.
It's like LFS-Tweak. To be honest I kinda prefer LFS-Tune; it's more performance-oriented than LFS-Tweak. Only the engine can be modified (at least in v 1.0) so you won't see a XRT with 2466'' rims and 4m wide tires. Goes to my favourites
Spotted bug: Engine size doesn't seems to be affected on XRT, you might want to check the program?
Your checking system never worked on any of my attempts, while using mine and reseting it to demo, or completely making up a user name and trying. Neither worked.
Ciph, keep this in mind, any knowledge of you sending your program around by means other than threads, but through PMs, you will be in serious trouble. Don't do it.