1. How to get the Id of the tradeskill recipe ?

  2. That depends entirely on where you're trying to get it from. Could you provide more information, please? If you're trying to get it from a recipe link, you can parse the link text.

  3. I want to get it from my Enchanting recipe list!

  4. Then use the tradeskill API. There's a category listing under the "Reference" section.