So as i was typing a reply, i pulled up your character so i could check something. You already have blacksmith to level 5 as of my search, so clearly what you did worked. So this answer is no longer for the OP, but incase anyone else has a similar issue and finds this thread in the future via some search.

The answer was in the class quests. Specifically, whatever class you start as you need to do the first 3 quests(lvls one five and ten) to be able to unlock most of the other classes in the game. There is an exception or two, as the OP unintentionally found, but in general its best to just do the class quests. As an added bonus, some of them give you extra skills to use in battle. If you no longer play the class and need to go back to do these quests for the unlock you can either equip your old weapon if you still have it or just purchase a cheap low level one from the vendor. Then once the quest you need is done, you can go back to being an ex-_____ and playing whatever it is you like.