"Shield: If you carry a shield, you can parry with it instead of your weapon, giving you a boon to the roll. There is no skill for shields – instead you can use any STR-based melee skill (i.e. any of them except KNIVES and STAVES) to parry with a shield."
I'm not the biggest fan of this ruling as is. I understand that by wielding a shield and using it to parry it grants a boon to your parry roll, but making that roll with just any old STR weapon skill seems like a miss. I would just assume make a shield skill since it can be used as a weapon as well or have the roll of parrying with a shield be a STR roll. At least being a STR roll offers a different 'feel' than rolling a weapon skill with a boon and I assume the same ballpark of success rate. That's just my opinion though.
I still think that giving shields their own skill would not be a good idea, sense it means if you wanna use a shield you gotta invest in the shield skill along with your weapon skill. And if you gotta invest in a second skill to survive, why not then invest in Evade that, while won't give you a boon, do's the same thing but better sense you can avoid most monster attacks with it?
The impression i get is that parrying is supposed to be the option you can always do as long as you have at leadt one decent weapon skill while evade is mainly useful if you invest in it. This makes shields useful in that as long your armed with a STR weapon you can defend yourself easier.
In fact when telling my beta group about parry and evade most woundered why you'd parry when evade seemed better, mainly being won over by the previously stated argument.