The idea proposed:
Runesmith: Allow them to make off hand items that give HP/MP bonuses.
Blacksmith: Allow them to forge special weapons and metal armor.
Alchemist: Is already getting a similar change.
Enchanter: Allow them to make special leather armor and maybe magic based weapons (Hoe/Wand etc)
Merchant: Just a toss out idea, but maybe allow them to make luck items?
As for specifics:
Blacksmith gets Axe/Sword/Spear(Shovel)/Dagger.
Weapons should be 2-3 Sharpness with no unbreaking. Have it give 5-10 HP. Maybe making it level 30 to make these and at level 60 it becomes slightly easier (Maybe gives slight unbreaking). Requires the appropriate amount of diamonds/iron to craft the tool, and then it should have <dungeon specific shard> that you combine a number of to create a haft/handle/guard which you then use to create the weapon. We could write it in as if the black smith is repairing long forgotten weapons.
Armor should have unbreaking 1-3 and give 2-5 HP per piece. Level 60 allow it to have fire/blast protect 1 or maybe have it the other way around. Should require some sort of dust/powder that can be used in crafting. Allowing the item to be made using the proper material and combining it with the item.
Runesmith gets the ability to craft books and paper that give 5-10 HP or MP if possible. Have it so the paper is for HP and Books for MP? To craft it should require bloodletting ink and Emerald Dust ink which drop in dungeons and have it combined with paper/books.
Enchanter can make hoes, maybe 2 different ones. Hoe 1 gives 5-10 hp and has kb 1 and hoe 2 has fire aspect 1 5-10 hp. Level 60 could add some unbreaking to it. Requires enchanted shaft to create hoe 1 and scorched shaft for hoe 2. Leather armor should be the same as the blacksmith, but require magic stitches
Merchant maybe can make armor or offhand luck items? Or have some way to buy/sell these items or materials?
@LordZelkova I'm not sure if this is what you meant, if not, just clarify and I can alter it.