Yeah I don't want to spoiler for anyone so don't click the hidden bit unless you've already completed the Trials of Shar. But you're right, I
spoiler
successfully persuaded the super-hench devil (that I'd been repeatedly warned to avoid because they're so powerful) to first kill all his henchmen, then kill himself, fight avoided
Act 2 has some awesome chances to bypass boss fights entirely... if you can pass multiple conversation checks in a row. My rogue almost won the bar conversation, but when you need to succeed 6 times in a row, luck is just not on your side.