I agree Movedalot, but it is, I think, almost impossible to know that people are feeling intimidated without being able to see their reactions. I think humour is difficult, Ella. I love verbal sparring, puns, satire, irony, but I don't particularly enjoy jokes and am hopeless at remembering / telling them. The things some people find funny, I find completely unfunny and sometimes offensive and I am sure the reverse is true.
I think if we kept possibly contentious subjects in AIBU then that might help.
I think if people feel bullied or intimidated it is important to remember that nobody on here has any power over you or your life.
On Mumsnet they often change identity after a particularly robust exchange.