"They should be able to wear any sort of armour they please and do better in it than any other guild though."

That is what I disagree with. A Paladin is a knight in shining (plate) armour, a fighter is not. Chain or scale should be the norm for a fighter, with leather and plate at the extremes.

Though I guess what I really wonder about here is the "up to X armour without penalty". Because it sounds like penalty will be based on guild, not skill(s). Is the intent to make it so that depending on guild, you get a penalty for wearing some armour, or is the idea that some skills will be affected by armour (and, in turn, affect armour, like defense giving a higher bonus with armour that is more "agile"). If it is the first, I think it is a bad way to do it. If it is the second, it could be interesting, and allow for people trying to use a guild in a way the creators didn't foresee, which is good IMO ;\)