You'll be fine. If you ever wear out the XTR...replace with a short cage. 11-34 is a wise choice for such tall meats. If you can afford it...check out the search function over at MTBR...there's a guy there who makes 30t middle rings. (ramped / un ramped) 30t up front with an 11-34 in the back would be a pretty decent setup for a 29'er.

11-32 is a tad steep....though...there are alot of rigid SS 29ers out there running steeper gearing than 32/32. It's all doable...just depends on how much you want to get off and walk.