The Legend of Tarzan (2016)

Chosen answer: Her feet are oriented correctly the entire time.

Chosen answer: It was a small, polished stone (probably a raw diamond) that Tarzan subsequently kept as a keepsake of his ape mother. You see him looking at it in a box at the beginning of the film, also.

Chosen answer: He's carrying a Holland and Holland "Royal" Double Rifle (popularly known as an "elephant gun"), which was introduced in 1918 using large-caliber rim-fire rifle cartridges. The H&H Royal Double Rifle was (and still is) available in a variety of calibers, the largest of which is a truly enormous.700 cal, typically used by big-game hunters on African safaris.