I think most of the items should indeed be random generation, but stuff like the Dragon Armour set and the Holy Items are far TOO random. It is beyond ridiculus that you can go to all the effort of doing the Holy Item quest and come out with a useless piece of junk.
It is also very silly that you can combine the Dragon Armour and the Heart Of The Dragon to end up with a far worse set of armour than your original Dragon Armour. All adding the Heart does is restat the item, it doesn't boost it at all.
So major items really need to be either fixed or very close to it, with everything else generated randomly.