If you are not using those protocols then there is no harm in removing them.
So for example if you don’t use Usenet then you don’t need 563 # snews
The worst that will happen if you remove something you need is that the traffic will not be allowed out and if you identify a port you need to access for outgoing web browsing then you can always add it back in.
This is for outgoing traffic related to web browsing. Any outgoing traffic sets up a connection which allows the responses from the website back to you because it’s part of the communication you triggered.
Incoming traffic is by default blocked and if you want it to be opened you have to create a firewall rule / port forward rule to do that. Generally this would only be needed if you had a web server or a mail server or something similar in your network that required to be accessed from the internet.