On Topic: The game seems to be pretty clear on what you can enchant different things with. I find that a bit annoying to be honest, as I like flexibility, but I suspect they did it to keep someone from making an OP armor set or something.
Absolutely correct. But they should have left that choice to they player. That is a reoccuring trend and should be an inherent freedom in an RPG - to create an artifact or a relic so powerful that you could conquer the world.
That doesn't mean your playstyle should mandate that you OP some gear, I know I wouldn't, this title all ready has enough difficulties with balances right out of the gate.