From my point of view, the TN (20-Attribute) isn't too high. As Francesco put it: You don't always need to roll. And if you do, usually not the whole group rolls, but the Hero, who is actually good at it.
Well and then there are useful items and Hope.
In the end, if you roll, it should be challenging, otherwise you wouldn't roll.
Same. We already had 3 sessions and no one complained so far.
Different character are better at different things, and it works. It came naturally without any pre-arrangement between players.
Everyone played their own character as they liked the most.