PoE goes a long way to avoid making some ways more EXP valuable and therefore more beneficial for power gamer. You don't get an EXP for the act of killing itself, especially killing people.
However I've noticed that Mechanics skill is an exception.
1) You get experience for disarming traps. No EXP for just avoiding traps - though of course it'd require some excessive scripting to notice player avoided traps and can't get EXP for disarming them anymore. This creates a cheesy tactics of returning to places were you couldn't disarm traps to get EXP even though it doesn't make sense in-universe.
2) When you see a locked door the smart thing is to unlock it if you have skill. You get EXP for that. If you already have the key then you're screwed cause it's probably quest item and you can't drop it. And you won't get EXP.
Those kinds of problems are balance issues cause they're easy to figure out, do not require any skill - only time and desire to reload, and don't make sense in-universe. I'm hoping to do Path of the Damned replay of the game and wonder if those are kind of things that will help me fight through the higher difficulty.