1) Yes, a spellbook can be enchanted. Complete Arcane has the relevant information.

2A) Complete Arcane doesn't have any enchantments that would repair damage. You could potentially use a mending or make whole contingent spell.

2B) Dunno.

3) Spellbooks are not magic items by themselves, and so cannot be treated like one. An enchanted one might be able to, as well as a blessed book, depending on whether you consider it 'consumable' (it can run out of pages).