Hello! I'm gonna answer all questions here.
1. This works with all cases, it's eventing so it's up to your decision which platform you want it to work on. Gamepad and Keyboard are already handled defaultly by RPG Maker. Mouse, Touch for mobile is also supported by the plugin.
2. It's Show Pictures. It's really up to your skill in eventing to create stuff. The higher your skill, the more you can do with this plugin.
3. The plugin manipulates Show Pictures and creates resizable text windows. Animated title screens? Possible. Gif and Mp4? You'll need a plugin that add that, then combine with this plugin.
4. Again, this plugin manipulates Show Pictures. And Show Pictures can only exist in scene map, not in RPG Maker turn-based battle.