Myrgard

Which of these files in the main directory can I get rid of? I am trying to clean all this shit up.

For cleanup, you can get rid of everything but Myth II.exe and Smackw32.dll if you want, but you probably want to keep the PDFs and Fear/Loathing as well. For directories, I think "Myth Versions" and "Storage" seems like things you invented. "Green Berets" shouldn't be needed as well. Not sure about "Interfaces"... I though those just go in plugins.

For 1.7.2, just download this, unzip to your myth directory with 7-zip, then you can run it if you want to run 1.7.2 for whatever reason (although not sure why you'd need to).

No, I just want to get rid of the 1.8 stuff here and reinstall in another copy. Looking at my directory, which of those little files do I NOT need?

What do you mean "1.8 stuff"? That doesn't make sense. You can't just delete some stuff there and have it run as 1.7.2... that's mainly the EXE (which is what I posted).

Ok forget the 1.8 "stuff." Looking at my list of files in that folder right now, which of those do I not need?

83kg dependencies?
cada dependcies? etc.
smackw32

The smacker file is needed for older versions of Myth2 and Fear, but not for 1.8.0. None of those "dependencies" files are default stuff. So they are safe to get rid of. You don't need that test pathfinding fix exe file either. "Myth II old" is likely the 1.3.0 exe. You can get rid of it if you want. Myth2_172 is probably the 1.7.2 installer. Safe to delete as well. The folders Demos, Green Berets, Interfaces, Myth Versions, and Storage are not default Myth folders. You made those and can remove them if you want. Interfaces are plugins so they are safe to drop into your plugins folder unless you have some really old ones from 1.4.x/1.5.x days that override the patches. The 3 files that start with GB are likely stuff from a Green Berets installer. Not needed for default Myth2. The rest are files Myth needs or that help you in some way.

My local folder has 2 observer constants folders. I want to say 1 is required for TFL and the other for SB?

I have ridiculous OCD when it comes to keeping things neat and simplified.

Myth2 only uses one set for everything. You probably renamed one to use a different one. Myth uses the one in the folder "observer constants". If you have more than one file in there, there may be a conflict and Myth will just pick one over the other.