One thing he asked me is do you roll for everything?
And this is something I'd thought about before: What principled ways can a GM call for a dice roll? This is the philosopher in me being concerned that I'm merely using intuitive feelings to decide when it's appropriate to ask players for a dice roll and not a rational principle. If a GM asked players to roll for everything, this would be principled. It would also be tedious and turn role play into nothing more than a dice game.
At the opposite end of absolutism one could never ask for a dice roll (in something that's intended to be a dice rolled rpg), but then it's not clear that there is a mutually agreed upon conflict resolution system between players and GM on how to decide outcomes - I'd worry a GM in such cases is being needlessly whimsical.
In the games we play it seems we're trying to have a happy medium. We want dice rolling to decide conflict resolution, but we don't want any trivial thing that could be contested to be rolled out, and we don't want to do away with dice rolling completely as then it's unclear why some things are successful and some things are not.
Attempts at a happy medium:
These are really just off the top of my head (which means I'll probably think about this more and post again on this later):
All significant actions ought to be dice rolled. This calls out for a definition of significant otherwise it's just a restatement of: We need a principled happy medium. Let's say significant actions are those that the story turns upon, that will alter characters depending on the outcome. For some, this might be problematic because many things that we do call for dice rolls may not fall under this. For more dice heavy gamers, this then would be seen as a bad principle. However, others might respond that maybe those gamers aren't being principled (or following a different one), and this principle would work for gamers who want to be more permissive on the minor details.
The principle might also depend on the kind of game being played: are the characters heroic/supernatural or mundane?
If the characters are in the first group, then it could be good to take for granted that they are capable of succeeding at many mundane actions without rolling. If they're in the second group this might not be assumed.
Those are my scattershot thoughts on returning to the issue of dice rolling.