Reloading Scripts Behavior Should reloading scripts with F8 cause issues with the UI, and Blender all together? It has been doing such to me (factory defaults), but I don't know much about the feature.  

A common issue arising is: 

Traceback (most recent call last):
  File "C:\Program Files\Blender Foundation\Blender\2.75\scripts\addons_contrib\
space_view3d_quickPrefs.py", line 939, in setup
    gllightpreset_chooseLoadLocation(1)
  File "C:\Program Files\Blender Foundation\Blender\2.75\scripts\addons_contrib\
space_view3d_quickPrefs.py", line 604, in gllightpreset_chooseLoadLocation
    filepath=bpy.context.scene.quickprefs.gllightpreset_importdirectory
AttributeError: 'Scene' object has no attribute 'quickprefs'


This is with factory defaults, but after reloading scripts. I have not changed the scripts folder either. Vanilla settings. This error will pop up every 100ms, until I enable the QuickPrefs addon from the Testing branch. 

I'm really not worried about the issue of quickprefs, more than I'm really trying to find answers to the following questions:

1. Is the reload scripts command (default F8), only reloading the base script folder built-in with the Blender install, or does it reload all scripts referenced in the instance?

2. Does the "Scripts" Folder setting effect what folder is reloaded when executing "Reload Scripts". 

3. Is it common for a brand new install, without any changes, or enabled addons to error when reloading scripts after it's very first startup?

The point of these questions is so that I may understand that portion of Blender quite a bit better, as well as know what is considered "normal behavior" before reporting bugs. My apologies for not being more clear.
Every addon uses a register function that allows it to add operators, panels, extra properties etc that it uses to work, it also has an unregister function to undo these changes when the addon is disabled.

If disabling an addon gives errors after being disabled that are related to properties or functions that it setup, then it is a bug in the addon that should be fixed.

You may notice that the addon you refer to is from addons_contrib, which is a collection of addons available that haven't been accepted as official addons to be included in release versions. Chances are this error is a known one and is one of the reasons it is still in contrib. In this case a release candidate is not being considered as a release version and includes the contrib addons, which may not be the best option.

While reloading scripts can help in some cases, it doesn't remove every change and start from scratch, for that you will need to quit then start blender. I believe reloading scripts relies on the unregister functions mentioned earlier to work properly.

Whether you are using a new install or an old one, it depends on the addon scripts enabled to whether any issues like this happen.