Well, you can still have items, so you are crafting them. I think crafting is neither evocation nor thaumaturgy, so you can take a focus item on it with one or the other.
Skill replacement are strictly speaking the realm of thaumaturgy and you can only put spells into an item that you can cast yourself. So that wouldn't be allowed, if you only have evocation. However, sometimes if it makes sense or if it is just a cool idea, I would allow someone to create a skill replacement item without having thaumaturgy. But that would be as an exception, not as a clever way to save the refresh you'd have to spend on ritual/thaumaturgy.
