WoW Questions

[Canyarion]

I think you can unlearn professions in your character screen. There should be a button 'unlearn this profession' in the skills tab.

Specialization starts at like level 250... Perhaps 200, I don't know, I only read about it.
www.worldofwarcraft.com

Edit: http://www.worldofwarcraft.com/info/professions/

For leatherworking, the subclasses are: Dragonscale, Elemental, Tribal.

Edit2: This page doesn't say much about specialization.

Edit3: "Specialization

At high levels, players have the ability to specialize as an Armorsmith or Weaponsmith. Additionally, Weaponsmiths can specialize as Swordsmiths, Axesmiths, or Hammersmiths. Decide what is more important to you such as weapons vs. armor. You'll be able to create specialized items that are very powerful and likely valuable."