I can only open a module (which is of course supported by KT) if the name of the .GIT file and the .ARE file are the same as the original module. But if I want to make my own module, I have to change the .GIT and .ARE files to something unique. So, if the module is opened in the Module Editor, it can only be made into a .mod file with the original .Git and .Are names. Does that make sense?

As an example: I want to make my own module based on 151HAR. I want to name my own module into, say, 450KAR. I rename the .GIT and .ARE files into 450KAR, not forgetting to change the .IFO file so it says 450Kar etc. Now I open the module with the Module Editor. But it says it doesn't work, the map isn't supported and all... I change the .GIT and .ARE file back into 151HAR and now it opens. After editing the module, I build it into a .mod, put it into the modules folder. But it doesn't open in Kotor2.

So I try to just save the progress I made in the Module Editor, and then change the .GIT and .ARE files back to 450KAR. Now the module loads, but everything I changed with the Module Editor can't be seen.

not forgetting to change the .IFO file so it says 450Kar etc.
Do you mean you re-named module.ifo or changed the reference within module.ifo? This file should not be re-named. There is no way to edit using the module editor without using the original names of the .git & .are. You have re-name them before building the .mod file. Also the module editor tends to currupt the .git file. After you make your edits and save, open the .git with K-gff and re-save it. Check out this post (http://www.lucasforums.com/showpost.php?p=2021727&postcount=4).

I've been doing this for the better part of two months. It's a bit tedious but it beats the heck out of editing modules manually.

Yes, thanks, that helped!