Well..the ads don't tell everything...and there is alot to tell so it can be confusing. Here is the detailed list url. No there is no diff I believe between pro and standard for those. Just improved in 4. The file support and audio may matter. If you don't need those or Amapi. Terrain and sky are good, but plants are kinda poor...may not need it tho. There are some texturing limitations too, but you can buy plugins for that...just keep the full picture. Many of the renders(everywhere) will use another package or plugins so it can be misleading. There is no direct flash export either w/o vectorstyle. http://www.eovia.com/products/carrara/carrara_full_features.asp

No need to think outside the box....
    Just make it invisible.