No, the Nikon D5100 supports a maximum video resolution of Full HD 1080p at up to 30 fps.
The EN-EL14 battery provides approximately 660 shots per charge based on CIPA standards, making it suitable for a full day of casual shooting.
No, the D5100 is not weather-sealed or waterproof. It should be protected from rain, moisture, and extreme dust during rental use.
It uses the Nikon F-mount. For autofocus to work, you must use AF-S or AF-I lenses, as the camera body does not have an internal focus motor.