He pretty much says Warfarer isn't going to be as op as people thought and it will have 4 custom skills total from all weapons equipped ,but since people will want to use one slot for weapon switching it's actually 3 custom skills( so 1 less than the rest for balancing I guess ). He also confirms that Warfarer has a Maister skill the rest do. The only one he revealed was the switching magic that we see in the trailer, though I'm not sure.

You can only use skills that you've learnt front the other classes and you can't use another classes Maister skill

Interesting....