So, I know how to use toon shading and freestyle pretty well. But, I made a really complicated with way too many vertices Pug model that I’d really like to put into Blender Render and use Toon Shading and Freestyle (with a Material Modifier on low threshold under color to get a multi-colored outline) but it would take way too long and make meaningless lines on the mesh with the settings I want to put on and probably take too long. Should I just remake it but with less vertices?
Well, probably - yes, you need to redo it…However you have this model as a basis and process is called “retopology” where you “draw” your desired topology on top of already made 3d form. This is much easier than to start from simple plane or cube and redo all again.
CGC, Kent Trammell has pretty well covered retopology in Creating a Realistic Head series.
For easier work on retopology you can drop some resolution of the Multirez mod, Apply it and use Decimate or Remesh modifiers to get workable face count while not loosing too much of a form. If you keep your HI rez sculpt mesh you can bake normalmap if that fits your Freestyle project. http://www.pasteall.org/blend/30688