The XLN folders reference the Online installer for addictive drums. I am not sure if you still need that folder for the operation of addictive drums once it is installed.
Addictive Drums folder is a default folder to save personal user presets that you make, Within this folder is another folder that says settings which is used for diagnostics. There is a text file that says
"By renaming this file to "do_trace.txt", you can force Addictive Drums (AD) to trace/log additional information about what it's doing.
This is useful for the XLN developers to get more information when AD isn't working as expected.
Next time AD is run, it will create a log text file ("AddictiveDrumsLog.txt") on your desktop.
There will be a red "..TRACING IS ON" text at the bottom of the AD interface to indicate this mode.
Remember to restore the name back to "dont_trace.txt" (or simply trash the "do_trace.txt" file if both files exist)"
If you don't care about this feature then it may be safe the move the folder to another location. anytime you save personal presets you will probably need to do it with a save as function. I think the default icon to quickly save will search for the default location in My documents.
To load or save a personal preset from another location just click on the VST icon at the top of the plugin next to the red X scroll down to save plugin and choose the new location of your folder.
The same thing applies to the Nomad folder. If you decide to move it and you want to save a user preset click on VST at the top and choose save preset. Then navigate to the location of your preset folder.
Same thing applies for loading factory presets and user presets within Nomad use the VST icon