I read somewhere that these crafts respectively fall under the mage, thief, and warrior class. I thought there were no set classes in the game. I hope this doesn't mean that I will be limited to one craft through the game or that the craft will arbitrarily be made more efficient through the use of the skills that govern the three archetype classes.

All 3 are skills, so you can max out all 3 if you like. Armoring is Smithing in Skyrim. It falls under the Warrior Nebula. There's no classes, but there's the 3 nebulas where the perk trees are.

Hmm, seems my last post was deleted somehow, Please use the search bar for premade topics, instead of spamming re talked about things.

OK. What do I search?

Yeah, the skills aren't under "classes" just categories of skills. There's magic skills, stealth skills, and combat skills. Each category has 6 skills, and the perks for each skill fall under the category of that skill.

Honestly, skill categories don't seem to matter, unless they haven't told us something about perks (perhaps there are perks under each category that affect things related to that category, like carry weight for combat).

Regardless, now that you mentioned this, I totally realize I'm going to make a character that uses all three crafting skills along with mercantile and speechcraft. He'll do woodcutting, cooking and other things (hopefully fishing exists as well), and hunt for pelts and sell all of the goods that he makes or finds. Basically, a complete merchant.

I love that TES allows you to do things like that, because these things are only really possible in an open world environment.