I'm trying to set up a VPN server on a Raspberry Pi at home to help some friends who live in a country where internet is severely filtered. So far I have found OpenVPN and PiVPN for this pourpose. However, I'm worried because I do not know these friends very well:

* What are the risks? For example can they access my home network (e.g. shared files)?
* What if they use my home network for illegal activities which are illegal in my country?
* Is there any way to do this without these concerns?

The goal is to provide some people with secure unfiltered internet connection. So out of the box solutions which do not hinder my own safety are also appreciated.