Thank you Michael.... your response puts things in perspective for me. So important when starting out.
Fortunately, the CNC machine I plan to buy (ShopBot) comes with Vectrix, so that solves relief type of work.
For detailed 2d or parametric, it seems Alibre will be a good companion, although I find it so clunky, they need to learn from you!
So for 4th axis indexer, NOT "wrapped" type of work...(helix as a 4D example) Moi seems ideal for this type of design, right? I realize I will need a good CAM program for the 4D, such as Proto as Vectrix only does 2.5D (wrap around), vs. 4D. This is what I have gathered from some of the experienced users. Any additional input would be helpful... thx again...