I've found that well-designed (i.e. open ended) standardised questions help normalise comparison between candidates. Especially helpful if you have many candidates in a pipeline and/or a pool of interviewers that compare notes.

Work samples are my #1 competence filter. They've also formed the basis of great interviews.

As for your second point, sometimes you want to hire a change agent. It takes skill and practice to distinguish toxic personalities from the merely disruptive. Again, standard questions designed from a perspective of empathy and experience have helped me.