These are required by other pieces of software to function correctly. You should make sure you select all needed dependencies as they are not automatically installed.
See more here: https://github.com/mcdevs/mark2/blob/master/USAGE.md
You should never run random scripts without first checking the source code. It's easy to check the source code of any script generated by Simple Server Setup. Simply download it and open it in your favourite text editor
Scripts generated by Simple Server Setup are not inherently malicious. However be warned as the advanced options contain open text fields which could contain anything, even something malicious! So avoid running scripts generated by people you do not trust.
This final year project has passed the ethical review in place at the University of Sussex
By default it will be your server IP. If you entered a domain it will be the domain you entered. For security reasons I recommend you don't use your IP or limit who can access it using allow & deny in Nginx.