great questions if you want to work alone...

if I was asked such questions I would run away from this company :)

In my opinion, the best approach is to talk about what a candidate knows better and how much details she knows about her personal work and products

I prefer to discuss candidate's recent tasks especially problems and how they have been solved and dig deeper trying to obtain details. Another way to have a look at the her source code and discuss it, at least ask for explanations.

For me it works well.