Reply to Planning on buying a VCI-100se

So I was looking at controllers recently and I stumbled upon the VCI-100se and I've decided that it was perhaps the best option for me as a beginner in the DJing art.

Although,before making my purchase,I have a few questions regarding the VCI-100se which are the following :

-Can I just plug the VCI-100se to my laptop, load up Traktor and get going ?

-What is the best version of Traktor to use in conjunction with the VCI-100se ( I currently have Traktor Scratch Pro 3) ?

-What is included with the VCI-100se ?

-Why do people buy the Audio4DJ or Audio2DJ soundcards and if I require them, what is the best option for me if I'm planning to play at some parties and stuff ?

Thank you in advance.