"요리책은 누구의 것입니까?"
Translation:Whose is the cookbook?
That's not totally improper but not a regular phrasing.
"Whose cookbook is it?" is maybe the best mix of literal translation and regular phrasing. "Whose cookbook is this?" is probably the most common phrasing but maybe requires some assumptions.
No. I'm not sure which you're seeing it as, -겠- is regular future and "을 거-" is intention future. 것 there is "thing"/"that" and "-입니까?" is just formal "이다?" Maybe the most literal translation that works in English would be "That cookbook is whose thing?" or "Whose thing is that cookbook?"