By all means, continue using The VSSProp for texture enhancement on your characters.  But do not use the GC script on those characters.  The purpose of the script is to add the necessary Gc nodes to all other props and objects in your scene.  You may possibly check the material room for proper placement; there are times when the script and object may not agree with the node logic.  As for the workflow, you could use several approaches which may work easiest for you.  For example, add your props and objects, apply the Gc script, then introduce your characters applying VSS last.  Or treat your characters first, save them out as .cr2 or .pz2, build your scene, then import them back in when everything is finalized.  Currently, I am using PoserPro which already has Gamma Correction built into its render engine.  I do not need to apply any further corrective action to my texture material; the software does it for me. 

Indeed, continue using the VSSPR3 prop, it is the best of the other versions.  And although it looks undaunting in the material room, it is also easier to use.  As you learn more about the material room and shader nodes, you will find yourselve checking each and every object you introduce into your scene for improvement.  Many vendors give you the basics, others will give you the kitchen sink!  It is ultimately up to you to decide if you are satisfied with the store bought package or whether you can improve on the product to give you the desired look you are seeking.