1. Lots of things! It's kinda hard to say, because they're designed to be versatile. They'd be mostly useful in fantasy combat situations, since the pack is focused on weapons and magical spells.
2. Sure. Not all the animations will fit perfectly-- but for the most part I tried to imagine how the animations could be used in turn-based battles and top-down action combat. A lot of the animations are variations of generic "impact" type effects, which would have use in lots of ways.
For more info, I'll paste this from the readme:
The primary goal of these animations is flexibility:
Weapon animations are designed for use in traditional RPG battles as well as action-RPG combat. Frames can be flipped or rotated for further variety of application. Impact and effect animations, such as the smoke or dust clouds, should have a wide variety of uses, including as environmental detail.
Some parts of animations can be used in combinations with other animations. Some animations can loop infinitely -- hopefully it's clear which ones are capable of this.
Here's an example of one of the sword animations used in a top-down action scenario. The animation is flipped so it can work in each direction:
Hope that helps.