Stuck on a few:
17d Culinary utensil for difficult terrains? (8) ?T???N??
22a Vacuous or stupid people (8) ??R???D?
28a Unusualness, a one-off (6) ??R???
24a Native American tribe from Nebraska, originally (6) ?A????
21d Intrepid, brave (6) ???O??
29a Lamentable, woebegone (8) ?A?H????