
It depends. vbWiki Standard is easier to install, but on the other hand, vbWiki Pro has quite a number of features missing from vbWiki Standard. For instance with vbWiki Pro you get skin integration, usergroup management, Admin CP to control vbWiki and MediaWiki's operation, etc. A more thorough comparison can be found over at our site.
If you are installing vbWiki Standard, you can rename the /vbWiki folder to something else, although this is not advisable.
Please notice that this folder (e.g. /forums/vbWiki) is never seen by your visitors. Instead your visitors will go to the folder where you installed MediaWiki (e.g. /wiki).
The folder where vbWiki is installed does not affect your forum or wiki URLs.