@memokal
Prometheus mentioned a bit about Crafting in the Q&As (Survival & Travel & Crafting & Building) about it.
Crafted Items will not directly make you stronger, as you know it from many other MMOs, like magic/rare/epic. But Items will have special Abilities to support your skills or makes you more surviable and something like that.
Per example: If you want to make an expedition in rough mountain areas, where it is cold, it is recommended not just to run in a shirt, but with a coat.
Just a simple example, but i think it it explains the system very well.
Many questions was answered in the Q&A, but for getting a full view to the possibilities we need to wait for more spotlights and the ingame experience in Alpha.