To simply use TOR you do not need to run any kind of guard/middle/exit relay (this has always been the case), but yes there is the risk of being held accountable for other users data while hosting an exit relay.

This hasn’t gone away thanks to any legal precedent as far as I’m aware, so I imagine it all depends on the tech literacy of your local jurisdiction & how good of a lawyer you can afford.

In theory yes, but practically speaking trying to access a lot of the modern web over TOR would be at best painfully slow and at worst almost impossible thanks to DDoS protection providers like cloudflare.

I promise you that like 90% of the creepy stories you’ve heard are people either exaggerating or just straight-up lying to sound cool on the internet. The kind of stuff that actually needs to operate over the TOR network doesn’t exactly want to be easily discoverable by normal people.

You’re no more likely to accidentally stumble across illegal / dangerous content while using TOR than you are while using any other browser.

Obligatory “PIA is owned by adware distributors” warning.