will there be weapon skills or will be players and npcs just be able to pick up any weapon and use it to full effect?
Not sure yet. You will probably be able to use any weapon when you pick it up but may have to have skills to use it properly or to good effect. For example, you could pick up a sword and swing it around but if you don't have default resting stances then everything you do will be awkward and take more time.
Sounds like Rubies of Eventide used to have; you could equip a heavy set of armor and a big axe, but if you don't have the right skills, you won't be able to move very fast and your attacks would be slow and clumsy.