but I am not even sure If I needed it or not.
Well, you should have clarified that in advance. There is a whole manual chapter on what research can be performed for free (and how), and which not.
Also all the data of my survey is not given to third parties?
Our Terms and Conditions says that your data will be yours, and we won't give it to anyone else. Of course, other parties, especially our hosting provider and the computer center are involved in prióviding the service. So, when it comes to personal data, they are formally data processors.