You don't have to run an exit. A middle node is as important as an exit. And running a non-exit relay is pretty hassle free. You will get blocked by some sites, especially banks and governments unfortunately so be aware of that if you want to run one at home. There is a list for ISPs that allow Tor nodes [0] but diversity is important so if you know an ISP with generous traffic allotments that's better. Just check the TOS that they don't explicitly forbid running a relay. Or you could run a bridge to help censored users connect to Tor.

There is also some information on the community site about running and setting up all kinds of relays or bridges [1]

[0] https://community.torproject.org/relay/community-resources/g...

[1] https://community.torproject.org/relay/

Having run an exit node for a couple of years, the worst part for me was the spam associated with torrent traffic. I got several notices per week of copyright requests, which I responded to with a form letter fuck off, but it was still obnoxious because my upstream required me to do so, creating a ticket that they would not close until I had responded.

As far as dark websites, you are supporting them whenever you create any node, because any node can act as a hop for onion sites. On the balance, I think that it is worth having anonymity through Tor, but I will admit that that balance often seems a razor's edge.