So for this part:

"""""""""""I completely get what you mean by "For this, we need to adjust the actual geometry of the font/letters and then determine what you want to call "depth"."
So if I were to use Moi3d, choose the Bookman Old Style font from 'Draw Solid', and I use say a 20 degree V bit, how would I go about creating the geometry?"""""""""""

You want to model the font to control the depth "You want"...

I would model my tool (You said 20 degree, but didn't include the diameter of the tool)

With the model of the tool, you can determine the width at the various depths of the VCutter. Then you would go to each letter in your font text, and do the modeling to constrain your desired depth.

A combination of separation, offsetting\drawing and rejoining things at the proper widths to stop the VBit at the depths you want

We can get into this if you want\need to. It would probably be a great exercise for me and others to see various techniques to do this.

Also, Still want to see Grendel's Input here..... Monster!