Characters can raise their attributes by exerting themselves and then recovering, up to a maximum score of 18. You’ll find details about this in the Resting section on page 27.
It doesn’t really function as a funnel. The chance of dying permanently increases the more Scars you accrue, since you’re rolling against them to see if you survive a mortal wound or not. In the current version to roll 2d6 vs the number of Scars you’ve accrued and if you roll over them, you gain a new Scar. This means that a brand new character with only 1 Scar can’t die permanently the first time they reach 0hp, since the minimum roll on 2d6 is 2.