Personally, I don't really like to set boundaries. I'll say anything, even if it offends. I don't like how people nowadays are such sensitive pussies that can't take even crude jokes, much less blatant honesty about a touchy subject.
The only thing I'd ever avoid speaking up on is anything that is potentially violence inducing, like politics. I'll mock religion and race for comedic effect, but never the political aspect of it.
I'll still mock people with sensitivities like those SJWs with a sexual identity focus, or those talking about something something equality, because it's bullshit to me, the world is never equal. Hell I'll even mock people who think crude sex jokes and sexual content is grossly inappropriate.