The book is for enchanting items on the anvil.
To make an anvil you need 31 iron ingots. In a crafting table grid, place 3 blocks of iron across the top, 3 iron ingots across the bottom, and an iron ingot in the center:
[] [] []
--
-- -- --
Then place the anvil, use it, place an item in the first slot, the book in the other. The enchantment costs Experience levels too (and you gain these gathering experience spheres by killing monsters, mining minerals, and smelting items.)
For example, a book of Sharpness III used on iron sword will make the sword cause 1.5 heart more damage on each hit.
You can enchant normal books too, using enchanting table - which might seem useless since the resulting book will have only one enchantment and you'll have to pay the exp cost twice (first, creating the book, and then again, enchanting the item with the book on the anvil). The serious advantage though is that the enchanting table gives enchantments randomly while the book gives the item exactly the enchantment of the book.
Imagine you want to make your diamond boots to have featherfalling enchantment. You can waste 40 diamonds on enchanting one pair of boots after another on the altar until you finally get the featherfalling - or you can use up a bunch of leather and paper until you get a book of featherfalling, then just apply it to a single pair of boots - 4 diamonds total.
Short answer: No, you don't need a Farmer. But, for two villagers, you need at least 6 doors (that lead to a covered area).
Long answer:
The key to finding the answer is found within your own question. "Additionally, ..." implies more information came before your quoted part of the Wiki.
From that same linked wiki: "Villagers will mate depending on the number of valid doors" Make sure you have enough. You need about 3 times more doors than villagers for them to even consider breeding. This was the sole factor in breeding in previous versions. Now, it's only the first part.
Also, my intuition says the chunk that contains the new village needs to be loaded for breeding to occur. This means you need to be close to the villagers for longer periods of time.
Lastly, they need to be close to each other to breed.
Hope that helps!
Best Answer
In your context of Singleplayer Hardcore, neither enchant is really useful.
Curse of Binding is just annoying, as the only way you could get the armour off you if you put it on would be to wear down the durability, which is risky as you need to take damage to do this.
Curse of Vanishing, you might as well put on all your items anyway as a flex, it's hardcore, so if you die, everything gets deleted anyway. Not sure on the mechanics, but it's possible that as it's a negative enchant, it makes the 'enchantment value' of the tool/armour lower, so it's actually cheaper to repair/combine at anvil.