Does class have an effect on interactions? Will my character be recognized for the Wizard/Priest/Barbarian he/she is?
I hate classless RPG systems. PoE has a strong class system, which is very good. Now if my character's class has an impact on the story telling, that would be even better. My favorite RPG is Gothic 2, in that game you will have to join 1 of 3 factions: Paladin, Mercenary or Fire Mage (priest). Depending on the faction chosen the whole game changes, sometimes in small ways, other times in a rather important ways.
Classless RPG system is the most unrealistic and roleplayingly weakest system any RPG can have. In real life (depending on the culture you hail from) your chosen proffession may have an even greater effect on you social standing (the interactions people will have with you) than your gender, wealth, physical attributes or mental attributes.
On the RPG side of things, classless system is only good for action, nothing else. Sure those games advertise that you can be anything you want, but only on the actions side. On the RPG side, you are nothing, not a great warrior, a powerfull wizard nor a divinely chosen priest. You Are Absolutely Nothing.